Free tool

Tankmate compatibility checker

"Will these fish get along?" Tick the ones you're considering and we'll check every pair for the clashes that actually matter — temperature, predators and shrimp, the betta solo rule, and water hardness — straight from our fact-checked care guides.

Pick the fish you want to keep together

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

Guidance, not a guarantee. Fish are individuals — temperament varies, and even a "yes" pairing needs the right tank size, groups and cover. The checks here come from ourfact-checked care guides; always read each species' guide too, and have a plan to separate fish if it doesn't work out. Pair this with thestocking calculator.