Calculator

Aquarium stocking sense-check

A conservative stocking check for community tropical, goldfish, betta and cichlid tanks.

Tank volume (litres)

Species type

Typical adult length of your chosen species (cm)

Filtration strength

Result

≈ 21 adult-sized fish, conservatively

Favour shoaling species kept in groups of 6 or more of the same kind; a heavily planted tank helps absorb waste swings.

This is a deliberately conservative sense-check, not a stocking guarantee. Never add fish to an uncycled tank — establish the nitrogen cycle first, test ammonia, nitrite and nitrate, and stock gradually over several weeks. Overstocking is one of the most common causes of preventable fish illness and death.