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Aquarium calculation reference

Formulae and conversion constants in one place, with enough context to avoid using the right number for the wrong job.

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Reference material you can audit

This section collects the constants, formulas and comparison tables used across the site. It is deliberately separated from care advice so you can tell which parts are arithmetic and which parts depend on equipment, animals or local conditions.

Formula library

Transparent reference data with notes on what the figure does and does not prove.

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Common tank-size comparison

Transparent reference data with notes on what the figure does and does not prove.

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Litres and gallons conversion table

Transparent reference data with notes on what the figure does and does not prove.

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Core constants

1 litre
1,000 cubic centimetres exactly.
UK imperial gallon
4.54609 litres.
US liquid gallon
3.785411784 litres.
Freshwater planning mass
Approximately 1 kg per litre for rough household load estimates; add every other component separately.

Use the reference pages when a calculator result needs context

The reference library exists to answer unit and formula questions without forcing every calculator page to repeat the same background. It covers gallon definitions, common tank-size examples and the formulas behind the tools. The calculators then link back here when a user wants to verify the maths.

Formula library

Reproduce the volume, water-change, turnover and electricity calculations by hand.

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Common aquarium sizes

Use example dimensions as a sense-check rather than treating model names as exact water volume.

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