Best Aquarium Size for Beginners: 10, 20, 29 or 40 Gallons?
Compare 10, 20, 29 and 40 gallon aquariums for beginners by stability, footprint, weight, stocking flexibility, maintenance and running cost.
Read guide →Getting started & setup
Getting started & setup
30 published guides in this cluster.
Can You Add Fish the Same Day You Set Up a Tank?
Same-day fish stocking is risky in a brand-new aquarium because biological filtration is not established. Learn the exceptions, safer alternatives and what to test.
Read guide →Can You Put an Aquarium on Furniture?
Before putting a fish tank on a desk, dresser or sideboard, check load capacity, rigidity, footprint, moisture resistance, levelling and the aquarium's required support pattern.
Read guide →Fish Tank Setup Mistakes Beginners Make
Avoid common new-aquarium mistakes including same-day stocking, untreated tap water, overfeeding, weak stands, incompatible fish and cleaning filters the wrong way.
Read guide →Freshwater Aquarium Setup Checklist for Beginners
Use this freshwater aquarium setup checklist to plan the tank, stand, filter, heater, water treatment, cycling, testing and first fish without missing a step.
Read guide →How Deep Should Aquarium Substrate Be?
Choose aquarium substrate depth for gravel, sand and planted tanks, including maintenance, plant roots, anaerobic pockets and how to calculate the volume needed.
Read guide →How Long Should a New Aquarium Run Before Adding Fish?
A new aquarium is ready for fish when biological filtration is established, not after an arbitrary number of days. Learn what to test before stocking.
Read guide →How Many Fish Should You Add at One Time?
Avoid overloading a cycled aquarium by adding fish in sensible batches. Learn how species group size, filter capacity and water testing determine the right number.
Read guide →How to Acclimate New Fish Safely
Acclimate new aquarium fish safely by matching temperature and water conditions, limiting transport stress and choosing when gradual or faster transfer makes sense.
Read guide →How to Add New Fish to an Established Aquarium
Add new fish to an established community tank with quarantine, compatibility checks, acclimation, gradual stocking and strategies to reduce aggression.
Read guide →How to Choose an Aquarium Stand
Choose an aquarium stand that supports the tank correctly by checking load, footprint, base support, levelling, moisture resistance and access for filters and maintenance.
Read guide →How to Choose Between Glass and Acrylic Aquariums
Compare glass and acrylic aquariums by weight, clarity, scratching, shape, support, repair, price and long-term maintenance before choosing a tank.
Read guide →How to Convert an Empty Tank Into a Planted Aquarium
Turn an empty aquarium into a planted freshwater tank by planning substrate, hardscape, low-demand plants, lighting, fertilisation, cycling and gradual stocking.
Read guide →How to Fill a New Aquarium Without Disturbing the Substrate
Fill a new fish tank without blasting craters into sand, gravel or aquasoil using a plate, bag or diffuser and a controlled partial-fill method.
Read guide →How to Level an Aquarium Before Filling It
Learn how to level an empty aquarium and stand, what to shim, what not to shim, and why support requirements differ between rimmed and rimless tanks.
Read guide →How to Quarantine New Aquarium Fish
Quarantine new aquarium fish before they join an established tank using a simple separate setup, dedicated equipment, observation and careful transfer.
Read guide →How to Rinse Aquarium Gravel and Sand Properly
Rinse aquarium gravel and sand without detergents, reduce dust and cloudiness, and know when specialist planted substrates need different handling.
Read guide →How to Set Up a Betta Tank Properly
Set up a proper betta aquarium with enough space, gentle filtration, stable warmth, a secure lid, soft decor, live plants and a completed nitrogen cycle.
Read guide →How to Set Up a Community Aquarium
Plan a peaceful freshwater community aquarium by matching adult size, water parameters, group needs, swimming zones, temperament and filtration capacity.
Read guide →How to Set Up a Fish Tank Without a Kit
Build a fish tank from separate components instead of a starter kit, choosing the aquarium, filter, heater, light and stand independently for a better-matched setup.
Read guide →How to Set Up a Freshwater Aquarium Step by Step
Set up a freshwater aquarium correctly from stand and substrate to dechlorination, cycling, testing and the first fish, with a practical beginner sequence.
Read guide →How to Set Up a Low-Tech Planted Aquarium
Build a low-tech planted aquarium without injected CO2 using easy plants, moderate lighting, suitable substrate, simple fertilisation and controlled stocking.
Read guide →How to Set Up a Quarantine Tank on a Budget
Build a low-cost fish quarantine tank with a clear tub or spare aquarium, sponge filter, heater, thermometer, lid and simple hides without cutting safety corners.
Read guide →How to Set Up a Shrimp Tank for Beginners
Set up a freshwater shrimp tank with mature biofilm, stable water parameters, shrimp-safe filtration, plants, hides and careful acclimation.
Read guide →How to Set Up a Species-Only Aquarium
Plan a species-only aquarium around one fish's adult size, social structure, water chemistry, habitat, feeding and breeding behaviour instead of a mixed community.
Read guide →New Aquarium Timeline: What Should Happen Week by Week
Use this new-aquarium week-by-week timeline to understand setup, cycling, water tests, first stocking and early maintenance without relying on fixed dates alone.
Read guide →Rimmed vs Rimless Aquariums: Pros, Cons and Safety
Compare rimmed and rimless aquariums by support, visual style, maintenance, lids, cost and installation safety before choosing a tank.
Read guide →What to Do During the First 30 Days of a New Aquarium
A practical first-30-days aquarium plan covering cycling, water testing, first fish, feeding, water changes, filter care and what not to change too quickly.
Read guide →What You Need for a Fish Tank: Complete Equipment List
A complete fish tank equipment list covering the aquarium, stand, filter, heater, lighting, water testing, conditioner, maintenance tools and optional extras.
Read guide →Where to Put a Fish Tank in Your Home
Choose the safest place for a fish tank by checking floor strength, stand stability, sunlight, radiators, sockets, water access, noise and maintenance clearance.
Read guide →Cycling & beneficial bacteria
Cycling & beneficial bacteria
30 published guides in this cluster.
Ammonia During Cycling: What Level Is Normal?
Understand ammonia readings during fishless aquarium cycling, why more ammonia is not always better and what to do if levels become excessive or fish are present.
Read guide →Can a Water Change Stall an Aquarium Cycle?
Water changes do not normally stall aquarium cycling because beneficial bacteria live mainly on surfaces. Learn when changing water helps and when untreated water causes problems.
Read guide →Can an Aquarium Cycle With the Lights Off?
Aquarium nitrifying bacteria do not need light to cycle a tank. Learn when keeping lights off can reduce algae and when live plants change the answer.
Read guide →Can an Aquarium Cycle Without a Filter?
An aquarium can develop nitrifying bacteria without a conventional filter, but stable biological capacity still needs oxygenated surface area and reliable circulation.
Read guide →Can Plants Cycle an Aquarium?
Live plants can absorb ammonia and other nitrogen compounds, but plant growth does not automatically prove a new aquarium is safe. Learn how plant-led cycling works.
Read guide →Can You Add Fish Before Nitrite Reaches Zero?
Do not normally add fish while nitrite is measurable in a cycling aquarium. Learn why zero nitrite matters and what to do if fish are already present.
Read guide →Can You Cycle a Tank Without Fish Food or Ammonia?
A conventional aquarium cycle needs a nitrogen source. Learn what can supply it, why an empty running filter may not cycle meaningfully and how planted tanks differ.
Read guide →Can You Use Filter Media From Another Tank to Cycle Faster?
Mature filter media can speed aquarium cycling dramatically, but only if the donor tank is healthy and the media stays wet and oxygenated during transfer.
Read guide →Cycling Myths That Cause New Tank Problems
Avoid common aquarium cycling myths about old water, fixed waiting periods, water changes, filter cartridges, bottled bacteria and nitrate readings.
Read guide →Do Bottled Bacteria Products Speed Up Aquarium Cycling?
Bottled bacteria can shorten aquarium cycling when the culture is viable and used correctly, but storage, product type, ammonia supply and testing still matter.
Read guide →Does Cleaning the Filter Kill Beneficial Bacteria?
Clean aquarium filters without destroying biological filtration by preserving mature media, avoiding untreated chlorine and restoring flow without sterilising the filter.
Read guide →Does Substrate Hold Beneficial Bacteria?
Aquarium gravel, sand and soil all grow beneficial biofilm, but the filter usually provides the most predictable high-flow biological surface area.
Read guide →Fishless Cycling vs Fish-In Cycling: Which Is Better?
Compare fishless and fish-in aquarium cycling by fish welfare, testing, water changes, speed and beginner difficulty, and learn why fishless cycling is usually the better default.
Read guide →How Long Can Beneficial Bacteria Survive Without Flow?
Beneficial filter bacteria can survive a temporary flow interruption, but oxygen falls inside stagnant media. Learn what matters during outages and filter maintenance.
Read guide →How Long Does It Take to Cycle an Aquarium?
Aquarium cycling often takes several weeks, but there is no fixed duration. Learn what changes the speed and which test results prove the cycle is complete.
Read guide →How Much Ammonia Should You Add for a Fishless Cycle?
Choose a controlled ammonia target for fishless cycling without overdosing. Learn why the correct dose depends on the method, product concentration and expected bioload.
Read guide →How to Cycle a Fish Tank: Complete Beginner Guide
Learn how to cycle a freshwater aquarium without fish, what ammonia, nitrite and nitrate mean, how to test progress and when the tank is ready for stocking.
Read guide →How to Know When Your Aquarium Is Cycled
Learn the test results that show a freshwater aquarium is cycled and why zero ammonia, zero nitrite and the ability to process a known ammonia load matter more than nitrate alone.
Read guide →How to Move a Cycled Aquarium Without Losing the Cycle
Move an established aquarium while preserving filter bacteria by keeping mature media wet, limiting downtime and restarting filtration quickly.
Read guide →How to Restart an Aquarium After a Cycle Crash
Recover from an aquarium cycle crash by protecting fish, restoring filter flow, preserving viable media, reseeding bacteria and testing until ammonia and nitrite return to zero.
Read guide →How to Seed a New Aquarium With Mature Filter Media
Seed a new aquarium safely with mature filter media from a healthy donor tank, preserve oxygen and moisture, and verify the cycle before adding fish.
Read guide →Nitrate During Cycling: What Level Is Normal?
Learn what nitrate means during aquarium cycling, why a rising or zero reading can both be normal, and when to change water before adding fish.
Read guide →Nitrite During Cycling: What Level Is Normal?
Learn why nitrite rises during aquarium cycling, why a high reading can persist for days or weeks and what zero nitrite means before stocking fish.
Read guide →What Happens to Beneficial Bacteria During a Power Cut?
A power cut stops filter flow and gradually reduces oxygen around beneficial bacteria. Learn how to protect biological filtration and restart safely.
Read guide →What Is a Silent Cycle in a Planted Aquarium?
A silent cycle uses strong plant growth to take up nitrogen before large ammonia and nitrite spikes develop. Learn the benefits, limits and safer way to verify it.
Read guide →What to Do If Ammonia Spikes After Adding Fish
Respond to an ammonia spike after adding fish with testing, conditioned water changes, reduced feeding, restored filtration and investigation of the new bioload.
Read guide →What to Do If Nitrite Spikes After Adding Fish
Handle a nitrite spike after stocking by using conditioned water changes, checking filtration and oxygenation, reducing extra bioload and testing until nitrite returns to zero.
Read guide →Why Did My Aquarium Cycle Crash?
Learn what can crash or weaken an aquarium cycle, including filter shutdown, chlorine, media replacement, medication, pH collapse and sudden bioload changes.
Read guide →Why Is My Aquarium Cycle Stalled?
Diagnose a stalled aquarium cycle by checking ammonia source, pH, KH, temperature, oxygen, filter flow, test-kit use and accidental bacterial damage.
Read guide →Why Is Nitrate Still Zero After Weeks of Cycling?
Zero nitrate during cycling can be caused by plants, source water, testing errors or an incomplete cycle. Learn how to tell which applies.
Read guide →Water chemistry & testing
Water chemistry & testing
30 published guides in this cluster.
Aquarium Test Strips vs Liquid Test Kits
Compare aquarium test strips and liquid test kits for speed, accuracy, cost, parameter coverage and everyday use, with practical guidance on when each makes sense.
Read guide →Aquarium Water Parameters Explained: pH, GH, KH, Ammonia, Nitrite and Nitrate
Understand pH, GH, KH, ammonia, nitrite and nitrate in freshwater aquariums, what each test means and why stable species-appropriate water matters more than chasing one perfect number.
Read guide →Can a Filter Remove Nitrate?
Learn why standard biological filters usually produce rather than remove nitrate, which specialised methods can reduce it and why water changes and plants remain the main controls.
Read guide →Can Live Plants Lower Nitrate?
Learn how live aquarium plants use nitrogen, which types remove nitrate fastest and why planted tanks still need testing, sensible stocking and water changes.
Read guide →Can You Use Tap Water in a Fish Tank?
Learn when tap water is suitable for aquariums, why chlorine or chloramine must be neutralised and what to test before using municipal water with fish.
Read guide →Do You Need Water Conditioner for Aquarium Water?
Learn when aquarium water conditioner is necessary, how chlorine and chloramine affect fish and bacteria, and when untreated private well water may be different.
Read guide →Hard Water vs Soft Water for Aquarium Fish
Understand hard and soft aquarium water, how GH and KH differ, which fish tend to prefer each and why matching your source water can simplify fishkeeping.
Read guide →How Long Should Tap Water Sit Before Adding It to an Aquarium?
Learn when standing tap water can remove chlorine, why it does not reliably solve chloramine, and why an aquarium dechlorinator is the safer routine choice.
Read guide →How Often Should You Test Aquarium Water?
Learn how often to test aquarium water during cycling, after adding fish, in an established tank and when something looks wrong, with a practical testing schedule.
Read guide →How to Lower Aquarium pH Safely
Learn how to lower aquarium pH safely by understanding KH, using RO water when appropriate and avoiding unstable acid dosing that causes rebound swings.
Read guide →How to Lower GH in a Freshwater Aquarium
Learn how to lower aquarium GH by diluting hard source water with RO or deionised water while avoiding unstable chemistry and mineral deficiency.
Read guide →How to Lower KH in an Aquarium
Learn how to lower aquarium KH by diluting hard alkaline source water with RO water and why forcing pH down without reducing buffering can cause rebound swings.
Read guide →How to Match New Water Temperature During a Water Change
Learn how to match replacement-water temperature during aquarium water changes without chasing impossible precision or causing avoidable thermal shock.
Read guide →How to Raise Aquarium pH Safely
Learn how to raise aquarium pH safely by checking KH, restoring buffering gradually and using controlled mineral sources instead of sudden chemical swings.
Read guide →How to Raise GH in a Freshwater Aquarium
Learn how to raise aquarium GH with remineralisation salts, mineral-rich media and controlled source-water changes without creating sudden chemistry swings.
Read guide →How to Raise KH in an Aquarium
Learn how to raise aquarium KH to improve buffering and pH stability using measured alkalinity supplements or gradual mineral sources.
Read guide →How to Read an Aquarium Water Test Correctly
Learn how timing, lighting, sample volume, reagent mixing, colour matching and storage affect aquarium water-test results and how to confirm doubtful readings.
Read guide →What Happens If You Forget Water Conditioner?
Learn what to do if untreated chlorinated tap water was added to an aquarium, how fish and beneficial bacteria can be affected, and which steps matter first.
Read guide →What Is a Safe Ammonia Level in a Freshwater Aquarium?
Learn the safe ammonia target for freshwater aquariums, why any detectable ammonia matters, what causes spikes and what to do when a test is above zero.
Read guide →What Is a Safe Nitrate Level in a Freshwater Aquarium?
Understand nitrate in freshwater aquariums, why there is no single universal safe number and how species, tap water, plants, feeding and water changes affect the target.
Read guide →What Is a Safe Nitrite Level in a Freshwater Aquarium?
Learn the safe nitrite target for freshwater aquariums, what a positive test means and the immediate steps to take when nitrite appears in a stocked tank.
Read guide →What Is GH in an Aquarium and Why Does It Matter?
Learn what aquarium GH measures, how calcium and magnesium affect fish, shrimp, snails and plants, and why species needs matter more than one universal target.
Read guide →What Is KH in an Aquarium and Why Does It Matter?
Learn what KH means in aquarium water, how carbonate buffering affects pH stability and why very low KH can contribute to dangerous pH swings.
Read guide →When Should You Use RO Water in a Freshwater Aquarium?
Learn when reverse-osmosis water is useful for hard tap water, sensitive species and breeding, why pure RO usually needs remineralisation and how to introduce it safely.
Read guide →Why Does Aquarium pH Change Overnight?
Learn why aquarium pH can fall at night and rise during the day, how plant and animal respiration changes CO2, and when a daily swing signals weak buffering.
Read guide →Why Is Aquarium pH Different From Tap Water?
Learn why aquarium pH can differ from tap water after aeration, biological activity, driftwood, substrate and carbonate buffering change the chemistry.
Read guide →Why Is My Aquarium Nitrate Always High?
Troubleshoot persistently high aquarium nitrate by checking source water, stocking, feeding, detritus, plant growth and water-change size.
Read guide →Why Is My Aquarium Nitrate Always Zero?
Learn why aquarium nitrate can stay at zero because of plant uptake, light stocking, source-water chemistry, test technique or an incomplete nitrogen cycle.
Read guide →Why Is My Aquarium pH Too High?
Find the common causes of high aquarium pH, including hard tap water, carbonate-rich rock and substrate, and learn when stability matters more than chasing a lower number.
Read guide →Why Is My Aquarium pH Too Low?
Learn why aquarium pH falls, how low KH, biological activity, driftwood and source water contribute, and how to correct low pH without sudden swings.
Read guide →Maintenance & Water Changes
Maintenance & water changes
25 published guides in this cluster.
Can You Do Too Many Water Changes?
Learn whether frequent aquarium water changes can harm fish, what actually causes problems and when repeated changes are the safest response to ammonia or nitrite.
Read guide →Do You Need to Vacuum Sand Substrate?
Learn how to clean aquarium sand without sucking it out, when surface siphoning is enough and when compacted or dirty areas need extra attention.
Read guide →How Long Can Fish Go Without a Water Change?
Learn why there is no fixed safe number of days without an aquarium water change and how stocking, feeding, plants, tank size and nitrate determine the real limit.
Read guide →How Long Can Fish Go Without Food?
Learn how long healthy adult aquarium fish can usually tolerate without feeding, which fish need more frequent food and how to plan feeding safely while away.
Read guide →How Much Water Should You Change in a Fish Tank?
Learn how much aquarium water to change based on nitrate, routine maintenance and emergency conditions, with examples for 10%, 25%, 30% and 50% changes.
Read guide →How Often Should Aquarium Filter Media Be Replaced?
Learn how replacement frequency differs for sponges, floss, biological media and chemical media, and why condition matters more than a single calendar interval.
Read guide →How Often Should You Change Aquarium Water?
Learn how often to change freshwater aquarium water based on nitrate, stocking, feeding, tank size and source-water chemistry rather than following one rigid schedule.
Read guide →How Often Should You Clean an Aquarium Filter?
Learn how often aquarium filters need cleaning, which signs matter more than a fixed calendar and how to preserve beneficial bacteria during maintenance.
Read guide →How Often Should You Clean Aquarium Gravel?
Learn how often aquarium gravel needs vacuuming based on stocking, feeding, plant cover and visible waste, and why rotating sections can be better than deep-cleaning everything.
Read guide →How to Clean a Canister Filter Safely
Learn how to clean a canister aquarium filter without losing beneficial bacteria, including media order, impeller cleaning, priming and leak checks.
Read guide →How to Clean a Hang-On-Back Filter Safely
Learn how to clean a hang-on-back aquarium filter safely, preserve beneficial bacteria, restore flow and avoid replacing mature media unnecessarily.
Read guide →How to Clean a Sponge Filter Without Killing Bacteria
Learn how to rinse and squeeze a sponge filter safely using old aquarium or dechlorinated water while preserving the biological colony and restoring flow.
Read guide →How to Clean Aquarium Glass Without Scratching It
Learn how to remove algae from aquarium glass safely, avoid trapped sand and gravel, and choose tools that suit glass or acrylic tanks.
Read guide →How to Clean Aquarium Rocks and Driftwood
Learn how to clean aquarium rocks and driftwood without soap, damaging surfaces or stripping useful biofilm unnecessarily.
Read guide →How to Deep Clean a Fish Tank Without Crashing the Cycle
Learn how to deep clean an aquarium in stages while preserving biological media, avoiding untreated tap water and preventing a maintenance-induced cycle crash.
Read guide →How to Do a Water Change Without Stressing Fish
Learn a calm aquarium water-change routine that avoids chasing fish, temperature shock, untreated tap water and unnecessary disruption to substrate and filter media.
Read guide →How to Maintain an Aquarium While on Holiday
Learn how to keep a freshwater aquarium stable while you are away, including feeding, lighting, sitter instructions, evaporation and equipment checks.
Read guide →How to Remove Algae From Aquarium Decorations
Learn how to remove algae from aquarium ornaments and hardscape using aquarium-safe scrubbing, soaking and rinsing without soap or harsh residues.
Read guide →How to Restart Aquarium Maintenance After Neglect
Learn how to recover a neglected aquarium gradually by testing first, restoring water changes, removing waste in stages and protecting biological filtration.
Read guide →How to Vacuum Aquarium Gravel Properly
Learn how to use a gravel vacuum to remove fish waste and uneaten food without stripping the whole substrate or disrupting your aquarium unnecessarily.
Read guide →Is a 50 Percent Water Change Too Much?
Learn when a 50% aquarium water change is safe, when it is useful for high nitrate or emergencies, and when large chemistry differences make caution necessary.
Read guide →Monthly Aquarium Maintenance Checklist
Use this monthly aquarium maintenance checklist to review filter condition, equipment, plant growth, hardscape, water trends and tasks that do not need doing every week.
Read guide →Should You Replace Aquarium Filter Media?
Learn which aquarium filter media should be replaced, which should be cleaned and reused, and how to avoid throwing away beneficial bacteria unnecessarily.
Read guide →Weekly Aquarium Maintenance Checklist
Use this practical weekly aquarium maintenance checklist for water testing, water changes, substrate cleaning, glass, plants, filter flow and equipment checks.
Read guide →What to Do With Your Aquarium Before Going on Holiday
Use this pre-holiday aquarium checklist for water changes, filter checks, lighting, feeding plans, top-up water and emergency contacts before you travel.
Read guide →Filters, Flow & Oxygen
Filters, flow & oxygen
25 published guides in this cluster.
Air Stone vs Sponge Filter: What Is the Difference?
Compare air stones and sponge filters: both use an air pump, but only a sponge filter provides substantial mechanical and biological filtration.
Read guide →Can Aquarium Filter Flow Be Too Strong?
Learn the signs of excessive aquarium flow and how to reduce current without sacrificing filtration or oxygenation.
Read guide →Can Fish Live Without a Filter?
Learn when fish can survive without a conventional filter, what filtration actually does and why most aquariums benefit from continuous biological filtration and circulation.
Read guide →Can You Over-Filter an Aquarium?
Learn why extra media capacity is usually safe, while excessive current, intake suction and unnecessary complexity can still cause problems.
Read guide →Canister Filter vs Hang-On-Back Filter
Compare canister and hang-on-back filters for media capacity, flow, maintenance, noise, cost and aquarium size.
Read guide →Do You Need a Filter in a Planted Aquarium?
Learn when planted aquariums still benefit from filtration, how plants affect nitrogen waste and why circulation and oxygen remain important.
Read guide →Does an Aquarium Need an Air Pump?
Learn when an aquarium needs an air pump, how surface agitation oxygenates water and when a filter already provides enough gas exchange.
Read guide →How Long Can Fish Survive Without a Filter Running?
Learn what happens during a filter outage, why oxygen falls quickly and how to protect fish and beneficial bacteria until filtration is restored.
Read guide →How Much Filter Flow Does a Freshwater Aquarium Need?
Learn how to choose aquarium filter turnover based on fish, tank layout, waste load and real-world flow rather than one rigid rule.
Read guide →How Much Surface Agitation Does an Aquarium Need?
Learn how to judge aquarium surface agitation for oxygen exchange without creating excessive current, splash or CO2 loss.
Read guide →How to Increase Aquarium Filter Flow
Restore weak aquarium flow by cleaning prefilters and impellers, checking hoses and outlet position, and improving circulation without unnecessary filter replacement.
Read guide →How to Position an Aquarium Filter Outlet
Position aquarium filter outlets to improve circulation, surface agitation and debris movement while avoiding excessive current for fish.
Read guide →How to Reduce Aquarium Filter Flow
Reduce aquarium filter current with outlet positioning, spray bars, baffles and prefilter sponges while keeping biological filtration running.
Read guide →Internal Filter vs External Filter
Compare internal and external aquarium filters for space, noise, media capacity, maintenance, flow and leak risk.
Read guide →Should You Run Two Filters on One Aquarium?
Learn when two aquarium filters improve redundancy, circulation and maintenance flexibility, and when a second filter simply adds cost and current.
Read guide →Signs Your Aquarium Needs More Oxygen
Learn the warning signs of low oxygen in a freshwater aquarium and the safest immediate steps to improve aeration and investigate the cause.
Read guide →Sponge Filter vs Canister Filter
Compare sponge and canister filters for biological capacity, current, maintenance, fry safety and large-tank use.
Read guide →Sponge Filter vs Hang-On-Back Filter
Compare sponge and hang-on-back aquarium filters for flow, media, maintenance, oxygenation, fry safety and noise.
Read guide →What Size Filter Do I Need for My Aquarium?
Choose an aquarium filter by real tank volume, stocking, media capacity and flow rather than relying on an oversized marketing label alone.
Read guide →Where Should You Put an Air Stone in a Fish Tank?
Learn where to position an aquarium air stone for better circulation and gas exchange without creating excessive current or bubble disturbance.
Read guide →Why Are My Fish Gasping at the Surface?
Find the main causes of fish gasping at the surface, including low oxygen, ammonia, nitrite, heat and gill problems, plus immediate actions to take.
Read guide →Why Is My Aquarium Filter Noisy?
Diagnose aquarium filter rattling, humming, splashing and gurgling by checking water level, trapped air, impellers, vibration and blockages.
Read guide →Why Is My Aquarium Filter Not Pumping Water?
Troubleshoot an aquarium filter that has stopped pumping by checking power, priming, water level, blockages, impeller condition and trapped air.
Read guide →Why Is My Canister Filter Losing Flow?
Restore lost canister-filter flow by checking prefilters, hoses, media, impellers, air locks and excessive head height.
Read guide →Why Is My Sponge Filter Barely Bubbling?
Fix a weak sponge filter by checking the air pump, airline, valves, diffuser, sponge clogging and water depth.
Read guide →Heating, Lighting & Equipment
Heating, lighting & equipment
25 published guides in this cluster.
Battery Air Pumps for Power Cuts: Are They Worth It?
Learn when a battery aquarium air pump is worth owning, what it protects during outages and how to use it as part of a simple emergency plan.
Read guide →Can an Aquarium Heater Be Too Powerful?
Learn the risks of oversizing an aquarium heater, including rapid temperature rise and failure consequences, and how to choose safer capacity.
Read guide →Can Aquarium Lights Be Too Bright?
Learn the signs aquarium lighting is too intense for your plants and fish, how brightness affects algae and how to reduce intensity safely.
Read guide →Can You Leave Aquarium Lights On Overnight?
Learn why aquarium lights should usually be switched off at night and how overnight lighting affects fish rest, plants and algae.
Read guide →Can You Put an Aquarium Heater Horizontally?
Learn when an aquarium heater can be installed horizontally and why the manufacturer's orientation and submersion instructions must come first.
Read guide →Do Coldwater Fish Need a Heater?
Learn when coldwater aquarium fish do and do not need a heater, why room-temperature stability matters and when a heater can still be useful as backup.
Read guide →Do Fish Need Darkness at Night?
Learn why aquarium fish benefit from a normal dark period, how light affects day-night rhythms and why blue moonlight should not stay on all night.
Read guide →Do Tropical Fish Need a Heater in Summer?
Learn whether tropical fish still need an aquarium heater in warm weather and why stable minimum temperature matters more than the season name.
Read guide →Do You Need a Background on an Aquarium?
Learn the practical benefits of aquarium backgrounds for fish security, glare reduction, hiding equipment and improving contrast.
Read guide →Do You Need a Lid on a Fish Tank?
Learn the pros and cons of aquarium lids for jumping fish, evaporation, heat retention, gas exchange, lighting and plant growth.
Read guide →Essential Aquarium Tools Worth Owning
Build a practical aquarium maintenance kit with the tools that save time, improve consistency and help you respond to common problems.
Read guide →Glass Lid vs Mesh Lid for Aquariums
Compare glass and mesh aquarium lids for evaporation, heat retention, jumping prevention, gas exchange, lighting and maintenance.
Read guide →How Long Does an Aquarium Heater Take to Warm a Tank?
Learn what controls aquarium warm-up time, including tank volume, heater wattage, room temperature, lid use and circulation.
Read guide →How Many Hours Should Aquarium Lights Be On?
Learn how to set an aquarium lighting schedule for fish and live plants, with practical guidance for new tanks, mature planted tanks and algae control.
Read guide →How to Choose Aquarium Lighting for Live Plants
Choose planted aquarium lighting by plant demand, tank depth, brightness control and spread rather than wattage or colour temperature alone.
Read guide →How to Tell If an Aquarium Heater Is Broken
Learn the signs of a failed aquarium heater, including temperature drift, stuck thermostats, no heat, visible damage and erratic cycling.
Read guide →Is One Large Heater or Two Small Heaters Better?
Compare one large aquarium heater with two smaller heaters for redundancy, heat distribution, cost and failure risk.
Read guide →What Size Air Pump Do I Need for My Aquarium?
Choose an aquarium air pump by tank depth, number of air-driven devices, desired airflow and pressure rather than tank volume alone.
Read guide →What Size Heater Do I Need for My Aquarium?
Size an aquarium heater by water volume, room temperature, target temperature and heat loss rather than a watts-per-gallon rule alone.
Read guide →What Temperature Should a Freshwater Aquarium Be?
Learn why there is no single ideal freshwater aquarium temperature and how to choose a stable range based on the species you keep.
Read guide →Where Should You Put an Aquarium Heater?
Position an aquarium heater near moving water so heat spreads evenly, while following the manufacturer's submersion and orientation requirements.
Read guide →White Light vs RGB Aquarium Lights for Planted Tanks
Compare white and RGB aquarium lights for plant growth, colour rendering and control, and learn why intensity and spread matter more than label alone.
Read guide →Why Do Aquarium Lights Cause Algae?
Understand how excess light contributes to aquarium algae and how photoperiod, intensity, nutrients, plants and CO2 interact.
Read guide →Why Is My Aquarium Heater Always On?
Find out why an aquarium heater runs constantly, including undersizing, cold rooms, heat loss, poor circulation and thermostat faults.
Read guide →Why Is My Aquarium Heater Not Heating?
Troubleshoot an aquarium heater that is not warming the tank by checking power, thermostat setting, wattage, placement, temperature and faults.
Read guide →Tank Size & Stocking
Tank size & stocking
25 published guides in this cluster.
10 Gallon Fish Tank Stocking Ideas for Beginners
Beginner-friendly 10 gallon stocking ideas using adult fish size, group behaviour, water quality and realistic maintenance rather than maximum fish counts.
Read guide →125 Gallon Aquarium Stocking Ideas
Stock a 125 gallon freshwater aquarium sensibly with large community schools, feature fish or species-focused setups built around adult size and behaviour.
Read guide →15 Gallon Fish Tank Stocking Ideas
Practical 15 gallon aquarium stocking ideas built around fish behaviour, adult size, shoal requirements and usable swimming space.
Read guide →20 Gallon High Stocking Ideas
Stock a 20 gallon high aquarium around its taller shape, with practical ideas for small community fish, behaviour and filtration.
Read guide →20 Gallon Long Stocking Ideas for Community Fish
Use the long footprint of a 20 gallon long aquarium well with realistic freshwater community stocking ideas and adult-size planning.
Read guide →29 Gallon Aquarium Stocking Ideas
Balanced 29 gallon freshwater stocking ideas using adult size, shoal needs, bottom area and compatible behaviour.
Read guide →30 Gallon Aquarium Stocking Ideas
Practical 30 gallon freshwater stocking ideas for shoaling fish, bottom dwellers and focal species without relying on crude fish-per-gallon rules.
Read guide →40 Gallon Breeder Stocking Ideas
Make the most of a 40 gallon breeder's wide footprint with community, species-focused and bottom-dweller stocking ideas.
Read guide →5 Gallon Fish Tank Stocking Ideas That Actually Work
Realistic 5 gallon freshwater stocking ideas focused on adult size, behaviour, filtration and welfare rather than squeezing in the maximum number of fish.
Read guide →55 Gallon Aquarium Stocking Ideas
Plan a 55 gallon freshwater aquarium around adult size, swimming length, social groups and compatible feature fish.
Read guide →75 Gallon Aquarium Stocking Ideas
Freshwater stocking ideas for a 75 gallon aquarium, from larger community schools to carefully planned feature-fish setups.
Read guide →90 Gallon Aquarium Stocking Ideas
Plan a 90 gallon freshwater aquarium around adult fish size, swimming room, territories, filtration and compatible social groups.
Read guide →Best Fish for a 10 Gallon Aquarium
Beginner-friendly fish choices for a 10 gallon aquarium, with guidance on adult size, group needs and why one coherent stocking plan beats a mixed collection.
Read guide →Best Fish for a 20 Gallon Aquarium
Good fish choices for a 20 gallon aquarium, including small schooling fish, bottom dwellers and peaceful focal species planned around tank shape.
Read guide →Best Fish for a 29 Gallon Aquarium
Choose suitable fish for a 29 gallon aquarium using adult size, social group needs, water chemistry and the tank's taller footprint.
Read guide →Best Fish for a 40 Gallon Breeder
Fish choices that make good use of a 40 gallon breeder's broad footprint, from schooling species and bottom dwellers to selected focal fish.
Read guide →Best Fish for a 5 Gallon Aquarium
See which fish genuinely suit a 5 gallon aquarium and why many common schooling fish need more swimming room than this small tank provides.
Read guide →Best Fish for a 55 Gallon Aquarium
Good fish choices for a 55 gallon freshwater aquarium, from larger schools and community fish to selected feature species that suit the long footprint.
Read guide →How Adult Fish Size Changes Stocking Decisions
Why aquarium stocking should always use adult fish size, body mass, behaviour and waste output rather than the size of juveniles in a shop.
Read guide →How Many Fish Can You Keep in a 20 Gallon Tank?
Why there is no single fish count for a 20 gallon aquarium and how adult size, species behaviour, group needs and filtration determine a sensible stocking level.
Read guide →How Many Fish Can You Keep in a 55 Gallon Tank?
Estimate 55 gallon stocking sensibly using adult fish size, swimming space, shoal needs, territories and filtration instead of a fixed fish count.
Read guide →How to Tell If an Aquarium Is Overstocked
Learn the practical signs of aquarium overstocking, from poor water quality and oxygen stress to aggression, weak shoals and constant maintenance pressure.
Read guide →Long vs Tall Aquariums: Which Fish Prefer Which?
Compare long and tall aquarium shapes for active schooling fish, bottom dwellers, deep-bodied fish and planted displays.
Read guide →Why Tank Footprint Matters More Than Gallons for Some Fish
Understand why aquarium length and floor area can matter more than total gallons for active swimmers, bottom dwellers and territorial fish.
Read guide →Why the One-Inch-Per-Gallon Rule Is Unreliable
Learn why the one-inch-per-gallon rule fails for aquarium stocking and which factors give a safer picture of real fish capacity.
Read guide →Species, Tank Mates & Behaviour
Species, tank mates & behaviour
40 published guides in this cluster.
Best Tank Mates for Angelfish
Choose angelfish tank mates by adult size, temperament, fin-nipping risk, swimming space and the cichlid's territorial behaviour.
Read guide →Best Tank Mates for Betta Fish
Choose betta tank mates by temperament, tank size, swimming zone and water needs, with safer community options and clear warning signs.
Read guide →Best Tank Mates for Bristlenose Plecos
Choose bristlenose pleco tank mates by temperament, bottom territory, water chemistry and feeding needs.
Read guide →Best Tank Mates for Cardinal Tetras
Choose cardinal tetra tank mates by school size, adult size, temperament and warm soft-water compatibility.
Read guide →Best Tank Mates for Cherry Barbs
Choose cherry barb tank mates by temperament, group size, adult size and compatible freshwater conditions.
Read guide →Best Tank Mates for Corydoras
Choose Corydoras tank mates that respect their social group, bottom-dwelling behaviour, feeding needs and preferred freshwater conditions.
Read guide →Best Tank Mates for Dwarf Gouramis
Choose dwarf gourami tank mates by temperament, swimming zone, fin-nipping risk and male territorial behaviour.
Read guide →Best Tank Mates for Guppies
Choose guppy tank mates by water hardness, temperament, fin-nipping risk, adult size and breeding pressure, with practical community options.
Read guide →Best Tank Mates for Harlequin Rasboras
Choose harlequin rasbora tank mates by temperament, school size, adult size and soft-to-moderate freshwater requirements.
Read guide →Best Tank Mates for Kuhli Loaches
Choose kuhli loach tank mates that respect their shy nocturnal behaviour, group needs, soft substrate and hiding places.
Read guide →Best Tank Mates for Mollies
Choose molly tank mates that suit their active behaviour, adult size and preference for harder mineral-rich water.
Read guide →Best Tank Mates for Neon Tetras
Choose neon tetra tank mates by temperament, adult size, water chemistry and swimming zone while protecting the tetra school's social needs.
Read guide →Best Tank Mates for Platies
Choose platy tank mates by temperament, hardness, adult size and breeding pressure, with practical community options and combinations to avoid.
Read guide →Best Tank Mates for Tiger Barbs
Choose tiger barb tank mates that can cope with fast schooling behaviour and fin-nipping tendencies without being bullied or stressed.
Read guide →Best Tank Mates for Zebra Danios
Choose zebra danio tank mates that can handle their fast swimming, social group needs and cooler-end tropical temperature preferences.
Read guide →Bristlenose Pleco vs Common Pleco: Size, Tank and Care
Compare bristlenose and common plecos for adult size, waste output, tank requirements, feeding and why common plecos outgrow many home aquariums.
Read guide →Can Angelfish Live With Guppies?
Learn why angelfish and guppies are an uncertain pairing, including predation, fin damage, water chemistry and future guppy fry.
Read guide →Can Angelfish Live With Neon Tetras?
Understand the risks of keeping angelfish with neon tetras, including adult mouth size, school behaviour, tank layout and why juvenile success may not last.
Read guide →Can Betta Fish Live With Corydoras?
Learn why Corydoras are often suitable betta tank mates, plus group-size, substrate, feeding and temperament requirements that still need to be met.
Read guide →Can Betta Fish Live With Neon Tetras?
Check betta and neon tetra compatibility, including school size, tank space, temperature overlap, fin-nipping risk and when to separate them.
Read guide →Can Betta Fish Live With Shrimp?
Learn when bettas and freshwater shrimp can share a tank, why predation risk never disappears and how cover, shrimp size and betta temperament affect the outcome.
Read guide →Can Bristlenose Plecos Live With Bettas?
Learn why bristlenose plecos and bettas can often coexist, plus the cave, feeding, tank-size and temperament checks needed first.
Read guide →Can Corydoras Live With Bettas?
Learn why Corydoras and bettas can often share a tank, plus the group size, substrate, feeding and temperament checks needed first.
Read guide →Can Gouramis Live With Bettas?
Understand why gouramis and bettas can be a risky combination because both are labyrinth fish that occupy similar zones and may become territorial.
Read guide →Can Gouramis Live With Tetras?
Learn which gourami and tetra combinations can work, including school size, fin-nipping risk, adult size and water requirements.
Read guide →Can Guppies Live With Bettas?
Understand why guppies and bettas are a risky pairing, including fin shape, temperament, water chemistry and when separation is the better choice.
Read guide →Can Guppies Live With Neon Tetras?
Compare guppy and neon tetra needs, including hardness, temperature, school size, feeding and how to decide whether your water suits both species.
Read guide →Can Mollies Live With Guppies?
Compare mollies and guppies for water hardness, adult size, feeding competition and livebearer breeding pressure.
Read guide →Can Neon Tetras Live With Bettas?
Assess neon tetra and betta compatibility using school size, tank space, temperature, fin-nipping risk and the individual betta's temperament.
Read guide →Can Neon Tetras Live With Guppies?
Compare neon tetra and guppy compatibility, including hardness, school size, breeding pressure and how to decide whether your water suits both species.
Read guide →Can Platies Live With Guppies?
Compare platies and guppies for water chemistry, temperament, feeding competition and livebearer breeding pressure.
Read guide →Guppy Male-to-Female Ratio Explained
Learn why mixed-sex guppy groups need more females than males, how chasing creates stress and when a single-sex group is the simpler option.
Read guide →How Many Angelfish Can You Keep Together?
Plan an angelfish group around adult size, territorial behaviour, pair formation and tank dimensions instead of a simple fish-per-gallon rule.
Read guide →How Many Corydoras Should Be Kept Together?
Learn why Corydoras need social company, why species matching matters and how tank footprint and adult size affect the right group size.
Read guide →How Many Kuhli Loaches Should Be Kept Together?
Learn why kuhli loaches are more confident in groups, how many to keep and why tank footprint, hides and feeding space matter.
Read guide →How Many Neon Tetras Should Be Kept Together?
Learn why neon tetras need a proper school, what six fish means as a minimum welfare baseline and why larger groups often behave more naturally.
Read guide →How Many Tiger Barbs Should Be Kept Together?
Learn why tiger barbs need a proper social group, how school size affects fin-nipping and why tank length matters for active barbs.
Read guide →How Many Zebra Danios Should Be Kept Together?
Learn why zebra danios need a social school, why six fish is a useful minimum and how larger groups affect behaviour and tank space.
Read guide →Molly Male-to-Female Ratio Explained
Learn why mixed-sex molly groups need more females than males, how persistent courtship causes stress and when single-sex groups are simpler.
Read guide →Platy Male-to-Female Ratio Explained
Learn why mixed-sex platy groups need more females than males, how courtship pressure creates stress and when a single-sex group is easier.
Read guide →Fish Health & Disease
Fish health & disease
25 published guides in this cluster.
Can Aquarium Salt Help Sick Freshwater Fish?
Learn when sodium chloride may be useful in freshwater fish care, why species tolerance matters and why aquarium salt is not a cure-all for every disease.
Read guide →Can You Mix Aquarium Medications?
Learn why mixing aquarium medications can be risky, when combinations may be justified and how to avoid overdosing, interactions and unnecessary treatment.
Read guide →Columnaris in Aquarium Fish: How to Recognise It
Learn the signs of columnaris in aquarium fish, why it can resemble fungus and why fast progression, gill involvement and ulcers require prompt attention.
Read guide →Dropsy in Aquarium Fish: Symptoms and Next Steps
Learn what dropsy means in aquarium fish, why pineconing and swelling are serious signs and what supportive steps to take while seeking a diagnosis.
Read guide →External Parasites in Aquarium Fish: Signs to Watch For
Learn the common signs of external parasites in aquarium fish, including flashing, excess mucus, visible spots and breathing trouble, and why diagnosis matters.
Read guide →Fin Rot in Aquarium Fish: Symptoms, Causes and Treatment
Learn how to distinguish fin rot from simple fin damage, what water-quality problems can contribute and when veterinary diagnosis or medication may be needed.
Read guide →Fish With a Bent Spine: Common Causes and What to Do
Learn why aquarium fish may develop a curved or bent spine, including congenital deformity, injury, nutritional problems and chronic disease.
Read guide →Fish With Torn Fins: Injury or Disease?
Learn how to tell a clean fin tear from fin rot, nipping or progressive disease, and what to check before using medication.
Read guide →Fish With White Spots That Are Not Ich
Learn what else can cause white spots or patches on aquarium fish, including fungus, lymphocystis, breeding tubercles, injury and bacterial lesions.
Read guide →Freshwater Ich: Symptoms, Causes and Treatment
Learn how to recognise freshwater ich, why white spot disease spreads quickly, what to check first and how treatment depends on the parasite's life cycle.
Read guide →Fungal Infections in Aquarium Fish: What They Look Like
Learn what common fungal infections such as Saprolegnia look like, why damaged tissue is vulnerable and how to distinguish fungus from bacterial lookalikes.
Read guide →How Long Should You Quarantine Fish After Treatment?
Learn why there is no single post-treatment quarantine period for every fish disease and how to use symptom-free observation, diagnosis and disease life cycle to decide.
Read guide →How to Dose Aquarium Medication Using Net Water Volume
Learn why aquarium medication should be based on actual water volume, how substrate and décor reduce capacity and how to calculate a safer dose.
Read guide →How to Keep Beneficial Bacteria Alive During Medication
Learn how to protect aquarium biofiltration during fish treatment, which practices threaten nitrifying bacteria and how to monitor for ammonia or nitrite spikes.
Read guide →How to Set Up a Hospital Tank for Sick Fish
Learn how to set up a simple hospital tank with stable heat, filtration, oxygenation and easy observation, plus how to avoid crashing an uncycled treatment tank.
Read guide →How to Sterilise Aquarium Equipment After Disease
Learn how to clean and disinfect aquarium nets, siphons and hard equipment after disease without accidentally transferring pathogens between tanks.
Read guide →Internal Parasites in Aquarium Fish: Signs to Watch For
Learn the common warning signs of internal parasites in aquarium fish, why weight loss and abnormal faeces are not diagnostic and when testing matters.
Read guide →Popeye in Aquarium Fish: Causes and Treatment
Learn what can cause one or both eyes to protrude in aquarium fish, when injury is more likely than systemic disease and what to check before treatment.
Read guide →Red Gills in Aquarium Fish: Common Causes
Learn what red or inflamed gills can mean in aquarium fish, including ammonia, nitrite, parasites, infection and normal colour variation.
Read guide →Should You Medicate the Whole Aquarium or Quarantine?
Learn when treating the display aquarium may make sense, when a hospital tank is safer and what to consider before exposing plants, invertebrates and the biofilter to medication.
Read guide →Should You Remove Carbon During Fish Medication?
Learn when activated carbon should be removed during aquarium medication, why it can adsorb some treatments and when carbon is useful after treatment instead.
Read guide →Swim Bladder Problems in Fish: Causes and What to Do
Learn why buoyancy problems are a symptom rather than one disease, what can cause floating or sinking and how to respond without guessing at treatment.
Read guide →Velvet Disease in Freshwater Fish: Symptoms and Treatment
Learn how freshwater velvet can appear as a fine dusty coating, why gill involvement can be serious and why correct antiparasitic treatment matters.
Read guide →When Should You Not Use Aquarium Salt?
Learn when aquarium salt may be a poor choice, including salt-sensitive fish, plants and invertebrates, uncertain diagnoses and treatments that already alter salinity.
Read guide →White Stringy Fish Poop: What It Can Mean
Learn why white stringy fish faeces can occur with fasting, mucus, internal parasites and other illness, and why it is not a diagnosis by itself.
Read guide →Feeding & Nutrition
Feeding & nutrition
15 published guides in this cluster.
Best Foods for Angelfish
Learn what freshwater angelfish eat, how to choose a complete staple and how to use frozen foods without encouraging overfeeding or competition.
Read guide →Best Foods for Betta Fish
Learn what betta fish eat, how to choose a quality staple food and when frozen or live foods can add useful variety without overfeeding.
Read guide →Best Foods for Bristlenose Plecos
Learn what bristlenose plecos eat, why algae alone is not enough and how sinking foods, plant matter and natural grazing fit a balanced diet.
Read guide →Best Foods for Corydoras
Learn what Corydoras catfish eat, why sinking food matters and how to make sure bottom-dwellers get enough food in a busy community aquarium.
Read guide →Best Foods for Guppies
Learn what to feed guppies, how to choose a complete staple and how plant matter, frozen foods and small frequent meals can fit a balanced diet.
Read guide →Best Foods for Neon Tetras
Learn what neon tetras eat, how to choose food small enough for them, and how to feed a shoal without leaving excess food in the tank.
Read guide →Flakes vs Pellets for Tropical Fish
Compare fish flakes and pellets for tropical aquariums, including nutrition, feeding behaviour, waste, portion control and which format suits different species.
Read guide →Frozen vs Live Food for Aquarium Fish
Compare frozen and live aquarium foods for nutrition, enrichment, disease risk, storage and convenience, with guidance on using both safely as part of a balanced diet.
Read guide →How Long Can Aquarium Fish Go Without Food?
Learn how long aquarium fish may cope without feeding, why species and age matter, and how to plan holiday feeding without relying on risky feeding blocks.
Read guide →How Much Should You Feed Aquarium Fish?
Learn how much food to give aquarium fish, how to judge portions, what uneaten food means and why feeding by observation beats rigid pinch rules.
Read guide →How Often Should You Feed Aquarium Fish?
Learn how often to feed aquarium fish, why species and life stage matter, and how to build a routine that avoids overfeeding and missed bottom-dwellers.
Read guide →How to Feed Bottom-Dwelling Fish in a Community Tank
Learn how to make sure Corydoras, loaches and plecos get enough food without overfeeding the whole aquarium, using sinking foods, timing and multiple feeding spots.
Read guide →How to Tell If You Are Overfeeding Fish
Spot the signs of overfeeding in an aquarium, including uneaten food, swollen bellies, excess waste, cloudy water and rising nitrate, and learn how to correct it.
Read guide →Should You Have a Weekly Fasting Day for Aquarium Fish?
Learn when a weekly fasting day may be reasonable for healthy adult aquarium fish, when it is unsuitable and why it is not a cure for chronic overfeeding.
Read guide →What Happens If You Overfeed Aquarium Fish?
Learn how overfeeding affects fish health and aquarium water quality, from uneaten food and ammonia risk to rising nitrate, algae and chronic maintenance problems.
Read guide →Algae, cloudy water & common problems
Problems & cloudy water
35 published guides in this cluster.
Do Algae Eaters Actually Fix an Algae Problem?
Learn what algae eaters can and cannot do, why species choice matters and why adding fish, shrimp or snails is not a substitute for fixing light and nutrient imbalance.
Read guide →How to Clear Green Water in an Aquarium
A practical step-by-step plan for clearing green aquarium water by testing water quality, controlling light, reducing excess nutrients and using UV when appropriate.
Read guide →How to Get Rid of Black Beard Algae
Learn how to identify and control black beard algae using manual removal, stable lighting and nutrients, plant health and cautious targeted treatment when necessary.
Read guide →How to Get Rid of Blue-Green Algae in an Aquarium
Learn how to identify blue-green algae (cyanobacteria), remove slimy sheets safely, improve circulation and maintenance, and avoid mistaking it for ordinary algae.
Read guide →How to Get Rid of Brown Diatom Algae
Learn why brown diatom algae appears in new aquariums, how to remove it safely and when patience, cleaning, plant growth and nutrient balance are enough.
Read guide →How to Get Rid of Green Hair Algae
Learn how to remove green hair algae by combining manual removal, balanced lighting, controlled nutrients and healthy plant growth instead of relying on quick fixes.
Read guide →How to Get Rid of Green Spot Algae
Learn how to identify hard green spot algae, scrape it safely from glass or acrylic, reduce excessive light and review nutrient balance without damaging plants.
Read guide →How to Get Rid of Staghorn Algae
Learn how to identify branching staghorn algae and control it with manual removal, stable lighting and nutrients, healthy plant growth and cautious targeted treatment.
Read guide →How to Reduce Algae Without Chemicals
A practical non-chemical algae-control plan using light management, manual removal, feeding control, healthy plant growth, water changes and sensible maintenance.
Read guide →How to Troubleshoot an Aquarium When Something Looks Wrong
A calm step-by-step aquarium troubleshooting process covering fish behaviour, water tests, temperature, filtration, recent changes, disease clues and when to seek expert help.
Read guide →New Tank Cloudy Water: Is It a Bacterial Bloom?
White or milky water in a new aquarium is often a bacterial bloom, but substrate dust and water-quality problems can look similar. Learn how to tell the difference.
Read guide →Why Are My Fish Chasing Each Other?
Learn why aquarium fish chase each other during feeding, courtship, territorial disputes and bullying, and how to tell normal behaviour from persistent harmful aggression.
Read guide →Why Are My Fish Dying One by One?
A step-by-step aquarium troubleshooting guide for repeated fish deaths, covering ammonia, nitrite, temperature, disease, toxins, compatibility and quarantine without guessing.
Read guide →Why Are My Fish Hiding All the Time?
Learn why aquarium fish hide, from normal species behaviour and new-tank stress to bullying, poor water quality, bright lighting and lack of suitable cover.
Read guide →Why Are My Fish Not Eating?
Troubleshoot appetite loss in aquarium fish by checking water quality, temperature, stress, diet, bullying and signs of illness before assuming the food is the problem.
Read guide →Why Are My Fish Staying at the Bottom of the Tank?
Learn when bottom-resting is normal and when unusual bottom-sitting can indicate stress, low temperature, poor water quality, bullying, exhaustion or illness.
Read guide →Why Are My Fish Suddenly Aggressive?
Learn why aquarium fish can become aggressive after maturity, spawning, tank changes, crowding or social imbalance, and what to check before moving or adding fish.
Read guide →Why Are My Fish Swimming Against the Glass?
Learn why aquarium fish glass surf, from new-tank stress and reflections to small groups, unsuitable conditions, territorial behaviour and poor water quality.
Read guide →Why Are My Fish Swimming at the Top of the Tank?
Learn when top-swimming is normal and when surface crowding or gasping points to low oxygen, heat, ammonia, nitrite or another water-quality problem.
Read guide →Why Are There Bubbles on Top of My Aquarium?
Learn which aquarium surface bubbles are normal, when foam suggests dissolved organics or poor water quality, and how bubble nests differ from a maintenance problem.
Read guide →Why Did My Fish Die After a Water Change?
Learn the main reasons fish can deteriorate after a water change, including chlorine, temperature shock, large chemistry shifts, disturbed waste and pre-existing water-quality problems.
Read guide →Why Did My Fish Die After Adding Them to a New Tank?
Learn why newly added fish can die after introduction, including an uncycled tank, ammonia or nitrite, transport stress, acclimation problems, incompatible water and disease.
Read guide →Why Does Algae Keep Coming Back After Cleaning?
Learn why aquarium algae returns after scraping, how light, nutrients, plant growth and waste create repeat outbreaks, and how to fix the cause instead of only cleaning symptoms.
Read guide →Why Does My Aquarium Smell Bad?
Troubleshoot bad aquarium smells from decaying waste, dead livestock, dirty filters, cyanobacteria and stagnant areas, with safe steps to correct the cause.
Read guide →Why Does My Fish Have Clamped Fins?
Learn why fish clamp their fins, how stress, poor water quality, temperature and disease can contribute, and what to check before treating the aquarium.
Read guide →Why Is My Aquarium Water Brown?
Learn why aquarium water turns brown, how to tell tannins from suspended waste and what to do when driftwood, botanicals or dirty water are responsible.
Read guide →Why Is My Aquarium Water Cloudy?
Diagnose cloudy aquarium water by distinguishing substrate dust, bacterial bloom, algae, overfeeding and suspended debris, then fix the cause without unnecessary chemicals.
Read guide →Why Is My Aquarium Water Foamy?
Learn why aquarium water develops foam, how dissolved organics, protein films, medications and surface agitation contribute, and when foam signals a water-quality problem.
Read guide →Why Is My Aquarium Water Green?
Learn what causes green aquarium water, how to distinguish a free-floating algae bloom from other cloudiness and the safest ways to clear it without destabilising the tank.
Read guide →Why Is My Aquarium Water Yellow?
Find the common causes of yellow aquarium water, including tannins, dissolved organics, ageing filter media and neglected maintenance, with safe troubleshooting steps.
Read guide →Why Is My Fish Bloated?
Learn why aquarium fish become bloated, how overfeeding differs from dropsy or egg-carrying, and which warning signs need prompt specialist attention.
Read guide →Why Is My Fish Breathing Fast?
Learn why aquarium fish breathe rapidly, including low oxygen, high temperature, ammonia, nitrite, gill disease and stress, and what to test first.
Read guide →Why Is My Fish Losing Colour?
Learn why aquarium fish can lose colour because of stress, lighting, diet, social status, temperature or illness and how to troubleshoot a sudden colour change.
Read guide →Why Is My Fish Lying on Its Side?
Learn when a fish lying on its side is an emergency, how to check water quality and temperature, and why balance problems need diagnosis rather than guesswork.
Read guide →Why Is My Fish Scratching Against Rocks?
Learn why fish rub or flash against rocks and decor, including irritation from water quality, parasites and gill problems, and what to check before medicating.
Read guide →Plants & planted tanks
Plants & planted tanks
25 published guides in this cluster.
Amazon Sword Care Guide for Aquariums
Learn Amazon sword care, including substrate depth, root tabs, lighting, crown placement, leaf melt and how large the plant can become.
Read guide →Anubias Care Guide for Aquariums
Learn how to grow Anubias in aquariums, including rhizome placement, lighting, fertilisation, algae prevention and propagation.
Read guide →Best Aquarium Plants for Beginners
Choose beginner aquarium plants that tolerate low-tech conditions, including Anubias, Java fern, Java moss, Cryptocoryne, Amazon sword and easy stem plants.
Read guide →Best Aquarium Plants for Betta Tanks
Choose betta-friendly aquarium plants that provide cover, resting leaves and gentle shade without crowding the surface or creating sharp hazards.
Read guide →Best Aquarium Plants for Gravel Substrate
Find plants that thrive in aquarium gravel and learn how root tabs, grain size and planting technique make inert gravel work well for planted tanks.
Read guide →Best Aquarium Plants for Sand Substrate
Choose aquarium plants that grow well in sand, including root feeders, rhizome plants and stems, plus tips on root tabs and grain size.
Read guide →Best Aquarium Plants for Shrimp Tanks
Choose shrimp-friendly aquarium plants that create grazing surfaces, shelter and stable low-tech growth, including mosses, Anubias, Java fern and floaters.
Read guide →Best Floating Aquarium Plants for Beginners
Choose beginner-friendly floating aquarium plants and learn how to manage light, surface coverage, flow and nutrient uptake.
Read guide →Best Low-Light Aquarium Plants Without CO2
Choose easy aquarium plants that tolerate low light and do not require injected CO2, with placement and feeding tips for a simple planted tank.
Read guide →Can Aquarium Plants Grow Without CO2?
Learn which aquarium plants grow without injected CO2, what limits growth in low-tech tanks and how lighting and nutrients should be balanced.
Read guide →Cryptocoryne Care Guide for Aquariums
Learn how to grow Cryptocoryne, including substrate, root tabs, lighting, crypt melt, propagation and why stable conditions matter.
Read guide →Do Aquarium Plants Need Fertilizer?
Learn when aquarium plants need fertilizer, which nutrients fish waste supplies, and how to choose root tabs or liquid fertilizer without overdosing.
Read guide →Hornwort Care Guide for Aquariums
Learn how to grow Hornwort floating or anchored, manage rapid growth, reduce needle shedding and use it as a low-tech nutrient-hungry plant.
Read guide →How to Propagate Aquarium Plants
Learn the main aquarium plant propagation methods for stems, runners, rhizomes, plantlets, mosses and floating plants.
Read guide →How to Stop Floating Plants From Covering the Whole Tank
Control fast-growing floating aquarium plants with regular thinning, floating rings and surface-flow management while preserving shade and nutrient uptake.
Read guide →How to Trim Aquarium Plants Without Damaging Them
Learn how to trim stem, rosette, rhizome, moss and floating aquarium plants cleanly without harming crowns, rhizomes or healthy new growth.
Read guide →Java Fern Care Guide for Aquariums
Learn how to grow Java fern, including lighting, rhizome placement, fertilisation, propagation and common causes of brown or damaged leaves.
Read guide →Java Moss Care Guide for Aquariums
Learn how to grow Java moss, including attachment, lighting, trimming, debris control and why this hardy moss is useful for shrimp and fry.
Read guide →Root Tabs vs Liquid Fertilizer for Aquarium Plants
Compare root tabs and liquid aquarium fertilizer, which plants benefit from each and when using both makes sense.
Read guide →Vallisneria Care Guide for Aquariums
Learn how to grow Vallisneria, including substrate, lighting, root feeding, runners, trimming and common reasons new plants melt.
Read guide →Water Wisteria Care Guide for Aquariums
Learn Water Wisteria care, including planting, floating, light, fertilisation, trimming and propagation for fast low-tech growth.
Read guide →Why Are My Aquarium Plants Melting?
Learn why aquarium plants melt after planting or parameter changes and how to tell normal transition from root, nutrient or lighting problems.
Read guide →Why Are My Aquarium Plants Not Growing?
Troubleshoot slow or stalled aquarium plant growth by checking light, nutrients, CO2 availability, substrate, temperature and recent transplant stress.
Read guide →Why Are My Aquarium Plants Turning Yellow?
Troubleshoot yellow aquarium plant leaves by checking old versus new growth, nutrients, light, root feeding and normal transplant adjustment.
Read guide →Why Do Aquarium Plants Get Holes in Their Leaves?
Troubleshoot pinholes and tears in aquarium plant leaves, including nutrient shortages, grazing damage, ageing leaves and mechanical injury.
Read guide →Substrate, hardscape & aquascaping
Substrate & aquascaping
25 published guides in this cluster.
Aquascaping Basics: Rule of Thirds, Focal Points and Depth
Learn beginner aquascaping composition using focal points, the rule of thirds, foreground-to-background depth, substrate slopes and negative space without sacrificing fish welfare.
Read guide →Are Rocks From Outside Safe for Aquariums?
Learn how to assess outdoor rocks for aquarium use, including contamination, mineral effects, sharp edges and why unknown stones should be treated cautiously.
Read guide →Can You Mix Sand and Gravel in an Aquarium?
Learn how sand and gravel behave when combined, how to stop them mixing, and when separate substrate zones work better than blended layers.
Read guide →Can You Put New Substrate Into an Established Aquarium?
Learn how to add new sand, gravel or planted substrate to an established aquarium without burying waste, stressing fish or destabilising the tank.
Read guide →Can You Use Garden Soil in a Planted Aquarium?
Understand the risks and benefits of garden soil in planted aquariums, including ammonia, cloudiness, caps, pesticides and why plain mineral soil matters.
Read guide →Dragon Stone vs Seiryu Stone for Aquascaping
Compare Dragon Stone and Seiryu Stone for aquascapes, including texture, colour, weight, brittleness and effects on aquarium pH and hardness.
Read guide →Gravel vs Aquasoil for Planted Aquariums
Compare gravel and aquasoil for planted tanks, including nutrients, pH effects, lifespan, root growth, maintenance and cost.
Read guide →How Long Does Driftwood Release Tannins?
Learn how long driftwood can stain aquarium water, why tannin release varies and how soaking, water changes and carbon can reduce brown water.
Read guide →How Much Gravel Do I Need for a 10 Gallon Aquarium?
Estimate gravel for a 10-gallon aquarium from footprint and planned substrate depth, including planted and decorative setups.
Read guide →How Much Gravel Do I Need for a 20 Gallon Aquarium?
Calculate gravel for a 20-gallon aquarium, including the difference between long and high tanks and how planted depth changes the total.
Read guide →How Much Gravel Do I Need for a 55 Gallon Aquarium?
Estimate gravel for a 55-gallon aquarium using base dimensions, average substrate depth and gravel density, with tips for planted layouts.
Read guide →How Much Sand Do I Need for a 10 Gallon Aquarium?
Estimate sand quantity for a 10-gallon aquarium using the tank footprint and desired depth rather than a one-size-fits-all pounds-per-gallon rule.
Read guide →How Much Sand Do I Need for a 20 Gallon Aquarium?
Work out sand quantity for a 20-gallon aquarium from footprint and average depth, including standard, long and high tank shapes.
Read guide →How Much Sand Do I Need for a 55 Gallon Aquarium?
Estimate sand for a 55-gallon aquarium using tank footprint, average depth and substrate density rather than a rough pounds-per-gallon rule.
Read guide →How Much Substrate Do I Need for My Aquarium?
Estimate how much aquarium substrate you need from tank footprint, average depth and substrate density, with guidance for planted and decorative layouts.
Read guide →How to Change Aquarium Substrate Without Crashing the Cycle
Replace aquarium substrate while preserving beneficial bacteria, protecting livestock and avoiding an unnecessary nitrogen-cycle setback.
Read guide →How to Prepare Driftwood for an Aquarium
Prepare aquarium driftwood by choosing safe wood, cleaning it without chemicals, soaking it, managing tannins and making sure it is waterlogged before use.
Read guide →How to Slope Aquarium Substrate for Aquascaping
Create a stable aquarium substrate slope using depth, retaining hardscape and perspective without letting the rear bank collapse forward.
Read guide →How to Test Rocks for Aquarium Safety
Check aquarium rocks for contamination, crumbling, carbonate content and water-chemistry effects before adding them to a stocked tank.
Read guide →Is Aquarium Sand Hard to Maintain?
Learn how aquarium sand maintenance differs from gravel, how to siphon waste without removing sand and how to prevent compacted dirty areas.
Read guide →Is Play Sand Safe for Aquariums?
Learn when play sand can be suitable for aquariums, what to check on the label, how to rinse it and when a dedicated aquarium sand is the safer choice.
Read guide →Is Pool Filter Sand Safe for Aquariums?
Learn when pool filter sand can be used in aquariums, which product details matter and how grain size and additives affect suitability.
Read guide →Sand vs Gravel for Freshwater Aquariums
Compare sand and gravel for freshwater aquariums, including plant growth, cleaning, bottom-dwelling fish, appearance and maintenance.
Read guide →Why Does Aquarium Sand Turn Black?
Learn why patches of aquarium sand can turn dark or black, including trapped organic waste, algae, mineral staining and low-flow compacted areas.
Read guide →Why Is Aquarium Driftwood Floating?
Learn why new aquarium driftwood floats, how long waterlogging can take and safe ways to secure wood while it becomes saturated.
Read guide →Cost, Safety & Practical Ownership
Cost, safety & practical ownership
20 published guides in this cluster.
Are Aquarium Starter Kits Worth It?
Decide whether an aquarium starter kit is good value by checking tank size, filter, heater, light, lid and what essential items still need to be bought separately.
Read guide →Can a Floor Support a Large Aquarium?
Learn how to think about aquarium floor loading using total setup weight, footprint, stand design, floor condition and placement, and when to get structural advice.
Read guide →Can You Put a Fish Tank Upstairs?
Learn what to check before placing an aquarium upstairs, including full setup weight, floor structure, stand footprint and when to seek structural advice.
Read guide →How Long Can Aquarium Fish Survive During a Power Cut?
Learn why there is no universal safe time for aquarium fish during a power cut and which factors determine oxygen and temperature risk.
Read guide →How Much Does a 10 Gallon Aquarium Weigh When Full?
Estimate the full weight of a 10 gallon aquarium including water, the empty tank, substrate and décor, and use the calculator for a safer total-load estimate.
Read guide →How Much Does a 20 Gallon Aquarium Weigh When Full?
Estimate the full weight of a 20 gallon aquarium including water, tank, substrate, hardscape and equipment, with a calculator for your actual setup.
Read guide →How Much Does a 55 Gallon Aquarium Weigh When Full?
Estimate the full weight of a 55 gallon aquarium including water, glass, substrate and hardscape, and learn why the final support decision should use actual setup weight.
Read guide →How Much Does a 75 Gallon Aquarium Weigh When Full?
Estimate the weight of a full 75 gallon aquarium including water, tank, substrate and hardscape, and plan support using the actual installation rather than a rough rule.
Read guide →How Much Does a Fish Tank Cost to Run Per Month?
Estimate monthly aquarium running costs from heater, filter, lighting, air pumps, water, food and consumables, and learn which equipment usually dominates electricity use.
Read guide →How Much Does It Cost to Set Up a Freshwater Aquarium?
Plan the real cost of a freshwater aquarium, including tank, stand, filter, heater, lighting, substrate, testing, livestock and the recurring costs beginners often miss.
Read guide →How Much Electricity Does an Aquarium Use?
Calculate aquarium electricity use from heaters, filters, lights and air pumps using watts, hours and heater duty cycle rather than unreliable one-size estimates.
Read guide →How to Keep an Aquarium Warm During a Power Cut
Learn how to slow aquarium heat loss during a winter power cut using insulation, room-temperature control and safe gradual measures without creating oxygen problems.
Read guide →How to Keep Aquarium Water Oxygenated During a Power Cut
Learn how to maintain aquarium oxygen during a power outage with battery air pumps, surface agitation and emergency manual methods while reducing oxygen demand.
Read guide →How to Leak-Test a Used Aquarium Before Setup
Learn how to leak-test a second-hand aquarium safely before bringing it into service, including inspection, staged filling, observation and what to do if a seam weeps.
Read guide →How to Move a Fish Tank to Another Room
Learn how to move an aquarium to another room without lifting it full, how to protect fish and filter bacteria, and how to restart the system safely.
Read guide →How to Move an Aquarium to a New House
Plan an aquarium house move step by step, including fish transport, filter-media protection, temperature control, tank packing and safe restart at the new address.
Read guide →How to Reduce Aquarium Electricity Costs
Cut aquarium electricity use without compromising fish welfare by reducing heat loss, choosing efficient equipment, controlling lighting and measuring real consumption.
Read guide →How to Transport Fish Safely During a Move
Learn how to transport aquarium fish during a house move using secure containers, temperature control, aeration and sensible journey planning.
Read guide →Used Aquarium Buying Checklist: What to Inspect
Inspect a second-hand aquarium for chips, cracks, silicone damage, frame problems, stand condition and equipment issues before buying, then leak-test it safely before setup.
Read guide →What to Do With an Aquarium During a Power Cut
Learn the priority actions for an aquarium power cut: maintain oxygen, protect temperature, stop feeding, preserve filter bacteria and restart equipment safely when power returns.
Read guide →Aquarium planning
Calculation & planning guides
13 published guides in this cluster.
Aquarium load planning basics
width=device-width,initial-scale=1" name="viewport"/> Aquarium Floor Load Basics — Total Weight, Footprint & Support Questions <meta content="Learn the arithmetic behind aquarium total weight and why structural safety depends on more than kilograms alone.
Read guide →Aquarium measurement checklist
width=device-width,initial-scale=1" name="viewport"/> Aquarium Measurement Checklist — Get Better Inputs Before You Calculate <meta content="Use a practical aquarium measurement checklist for internal dimensions, water line, substrate, hardscape and equipment before running volume, weight or water-change calculations.
Read guide →Aquarium running-cost planning
width=device-width,initial-scale=1" name="viewport"/> Aquarium Electricity Running Cost — Heater Duty Cycle, Filters & Lighting <meta content="Understand the main drivers of aquarium electricity use and build a more realistic running-cost estimate than assuming every device runs at full power all day.
Read guide →Aquarium volume by shape
width=device-width,initial-scale=1" name="viewport"/> Aquarium Volume by Shape — Rectangular, Cylinder & Bow-Front Planning <meta content="Compare the volume formulas used for rectangular tanks, cylinders and other aquarium shapes, and learn when manufacturer capacity data is safer than a rough geometry estimate.
Read guide →Choosing a filter-turnover target
width=device-width,initial-scale=1" name="viewport"/> Choosing an Aquarium Filter Turnover Target — What L/h Does and Does Not Tell You <meta content="Understand how turnover is calculated, why a single target does not suit every aquarium and how rated flow differs from delivered flow.
Read guide →Gross volume vs actual water volume
width=device-width,initial-scale=1" name="viewport"/> Gross vs Actual Aquarium Water Volume — Why the Numbers Differ <meta content="Understand the difference between nominal tank size, geometric gross volume and the amount of water actually in an aquarium after substrate, décor and the air gap.
Read guide →How much aquarium substrate do you need?
width=device-width,initial-scale=1" name="viewport"/> How Much Aquarium Substrate Do I Need? Depth, Litres & Bag Weight <meta content="Work out aquarium substrate volume from footprint and average depth, then convert to product weight using manufacturer coverage or an entered bulk density.
Read guide →How much does a full aquarium weigh?
width=device-width,initial-scale=1" name="viewport"/> How Much Does a Full Aquarium Weigh? Water, Glass, Substrate & Stand <meta content="Estimate full aquarium weight by adding water, tank, substrate, rock, equipment and stand rather than assuming tank litres equal total kilograms.
Read guide →How much water should you change?
width=device-width,initial-scale=1" name="viewport"/> How Much Aquarium Water Should You Change? Percentage Maths Explained <meta content="Learn how water-change percentage maths works, why actual tank volume matters and why the correct maintenance amount depends on measured water quality and the setup.
Read guide →How to calculate aquarium volume properly
width=device-width,initial-scale=1" name="viewport"/> How to Calculate Aquarium Volume in Litres & Gallons <meta content="Learn how to measure aquarium water volume correctly, choose the right formula and convert litres into UK and US gallons without mixing the two gallon systems.
Read guide →Internal vs external aquarium dimensions
width=device-width,initial-scale=1" name="viewport"/> Internal vs External Aquarium Dimensions — Which Measurements to Use <meta content="Learn when aquarium calculations should use internal rather than external measurements and how glass thickness, trim and water line change the volume estimate.
Read guide →Nominal capacity vs real tank volume
width=device-width,initial-scale=1" name="viewport"/> Nominal Aquarium Capacity vs Real Water Volume <meta content="Understand why a tank sold as 100 L, 120 L or 200 L may hold a different amount of water in normal use and how to choose the right number for each calculation.
Read guide →US gallons and UK gallons are not the same
width=device-width,initial-scale=1" name="viewport"/> US Gallons vs UK Gallons for Aquariums — Conversion Guide <meta content="Understand the difference between US and UK imperial gallons, convert both to litres and avoid aquarium mistakes caused by the ambiguous word gallon.
Read guide →How this library is built
Each page targets a distinct user question and links into relevant tools and neighbouring guides. We avoid keyword-swapped variants, expose calculator assumptions and treat fish welfare and health claims conservatively.