Review water ranges, group sizes, tank dimensions, and unresolved behavior constraints. No opaque stocking score. No false compatibility guarantee.
No cloud sync. Avoid saving sensitive records on a shared browser.
Illustrative starting inputs. Replace them with your own measurements and evidence.
Volume and turnover set the frame; species rows carry the individual compatibility review.
This is a constraint checker using your measurements and husbandry inputs, not expert approval to stock the aquarium.
Open each species row below to compare adult size, temperature, pH, and hardness. A zero queue means no entered rows need review.
| Category | Value |
|---|---|
| Top | 0 |
| Mid | 0 |
| Bottom | 0 |
| Unknown zone | 0 |
| No matching records. Add records or adjust your filters. | |||||||
| No matching records. Add records or adjust your filters. | ||
Usable liters = internal length × width × height in centimeters ÷ 1,000 × fill percentage − displacement.
Each species is checked against its entered adult-space, social-group, temperature, pH, and hardness requirements. Behavior and missing evidence remain explicit warnings.
Bioload index, stocking %, care level, and the compatibility matrix are computed only from what you enter; they are reference approximations, not verified husbandry approvals.
A tank entered as 100 × 40 × 40 cm at 95% fill with 5% displacement yields 149.025 L, displayed as 149 L. A 600 L/h flow yields 4.026 turnovers per hour, displayed as 4×/hr. Those outputs describe the entered habitat; they do not approve a stocking plan.
Each species row compares entered temperature, pH, and hardness with the row’s adult-size and care constraints. Keep the source note with the row and treat unknown values as a reason to review, rather than as a pass.
RSPCA fish-care guidance describes cycling and water quality as core husbandry work. Use the cycle control to record what you know, then confirm readings with a current test method before adding fish.
Estimate actual water volume from internal dimensions, fill height, and displacement, not the nominal tank label.
Check each species against entered adult-space requirements, minimum social group, and measured water ranges.
Keep cycle status, aggression, missing husbandry evidence, and other uncertainty visible. Passing numeric checks never becomes a guaranteed compatibility score.
Read the full methodologyPrioritize animal welfare. A specialist-reviewed husbandry plan and a properly cycled, stable aquarium are required; this calculator is not approval to add fish.
These are reference sources, not evidence that example records have been verified. Imported records retain the source links you provide.
Internal length × width × water fill height gives the wetted volume, then the substrate/decor displacement you enter is subtracted. This is closer to the real water volume than the nominal tank size printed on the box.
Your measured filter flow is compared against a general reference turnover rate for the filtration type you select (sponge, HOB, canister, sump, or undergravel). It is a reference comparison, not a sizing guarantee for your specific stock.
Numeric range checks (space, group size, temperature, pH, hardness) never resolve behavior compatibility, unverified husbandry evidence, or an unset cycle status. Those stay flagged for manual review even when the measured ranges pass.
If the aquarium cycle is not confirmed 'Yes', the result status is set to a warning regardless of the other checks, because adding fish to an unstable nitrogen cycle is a welfare risk independent of stocking math.
No. All calculations run in this browser. Saved plans, CSV imports, and JSON exports stay on your device unless you explicitly export or share a link.
No. Presets only fill in tank dimensions for common gallon sizes. Species rows start empty and require your own independently verified adult size, group size, and water-range requirements.