Compatibility: which fish live together

Does the same water suit them (temperature, pH)? Is one small enough for the other to eat? Does one chase or nip the other? If the answer to either of the last two is “yes”, they do not go together, however nice they look.

These rules are approximate. Fish have personalities, and tank size changes a lot.

Peaceful, but they grow. A grown angelfish may eat very small fish, such as small tetras. They usually do well with medium-sized peaceful fish. Avoid fin-nippers, as angelfish have long, delicate fins.

Tetras are generally peaceful shoaling fish; keep them in groups of six or more. Tiger barbs are boisterous and can nip fins, so keep them in a bigger group and away from slow, long-finned fish.

Goldfish prefer cooler water than most tropical fish and produce a lot of waste. Put them with tropicals and one group is too cold, the other too warm. Fancy varieties are also slow and easy targets for nippers.

That is why we recommend them in their own roomy tank with strong filtration, not as “one more fish” in a tropical tank.