Finfernhonest freshwater care

Free tool

Stocking & tank-size calculator

The number-one beginner mistake is too many fish in too little water. Tell us your tank and your wish-list — we'll check each fish against its fact-checked minimum tank and group size, flag any clashes, and give you an honest read on how full the tank is.

1 · Your tank
…or work it out from tank dimensions (cm)

A rough guide — real filled volume is a little less than the glass dimensions.

2 · Your fish

Only fish with a fact-checked Finfern care guide appear here — more as we source them.

An honest tool, not a promise. The minimum-tank and group checks come straight from our fact-checked care guides. The "how full" bar is a rough estimate — real capacity depends on filtration, plants, feeding and maintenance. The only true judge is your water: test your nitrate, and readhow big a tank does my fish need? andthe nitrogen cycle.