Primary external references
The arithmetic on this site is original and independently reproducible. External references are used for husbandry context and manufacturer-specific examples, not copied as replacement content.
- RSPCA — choosing an aquarium and fish environment: water quality, cycling, overcrowding and the limits of simple volume-per-length guidance.
- Ornamental Aquatic Trade Association (OATA): UK ornamental-aquatic welfare and care information.
- EHEIM UK catalogue: manufacturer heater sizing ranges used only as a labelled reference example.
