Convert an aquarium’s feeding plan and routine water-change plan into practical daily quantities. Enter tank volume, estimated fish biomass, daily feed rate, weekly water-change percentage, and displacement from substrate or décor. The calculator returns daily feed mass, average daily replacement water, and the actual weekly water-change volume for the usable water volume.
The main result expresses a weekly change as an average daily water requirement for planning and storage. It does not mean the change must be divided into seven daily changes.
Feeding and water-change needs vary by species, temperature, filtration, water tests, life stage, and food energy density. Use observed condition and water quality to adjust the entered rates.
For a 55-gallon tank with 12% displacement, 500 g of fish, a 1.5% daily feed rate, and a 25% weekly water change: usable water is 48.4 gal, the weekly change is 12.1 gal, the daily water equivalent is 1.73 gal, and feed is 7.5 g/day.
No. Use it to check arithmetic and planning assumptions, then follow the applicable veterinarian, product label, welfare standard, or qualified care guidance.
A zero is accepted only where it represents no cost, no feed, no water change, or another valid absence. Values used as divisors or required physical dimensions must be greater than zero.
Actual results depend on conditions not fully represented by a compact model, including animal needs, measured consumption, losses, operating practices, and local prices.
Keep the unrounded value for planning. For medication or treatment measurements, use only the rounding and measuring method approved on the label or by the responsible professional.
Update them whenever weight, occupancy, tank volume, husbandry routine, prices, equipment use, or the underlying care plan changes.
| Input type | How to choose it |
|---|---|
| Physical measurement | Use an observed or measured value in the displayed unit. |
| Rate or percentage | Use the applicable care plan, product label, or operating record. |
| Planning period | Keep the period consistent with the formula and result. |