Tankmate compatibility checker

A male betta is best kept SOLO — it's a solitary fish and tankmates are hit-or-miss, so only try them in a properly sized, planted tank and always have a backup tank ready. If you do, choose calm, non-nippy, non-flashy species (small peaceful catfish or snails), never fin-nippers or other bettas. Avoid dwarf shrimp: a betta will often eat them.

No — goldfish are coldwater fish and tropical community fish need a heated tank, so the two can't share one temperature. Goldfish also grow large and produce a heavy waste load, and will eat small fish and shrimp. Keep goldfish in their own unheated, oversized tank; keep tropicals together in a heated one.

Dwarf shrimp are safest in a shrimp-only tank or with tiny, peaceful, small-mouthed fish (nano tetras and rasboras, otocinclus, snails). Most other fish — bettas, angelfish, gouramis, larger tetras, all cichlids and loaches — will hunt shrimp or at least eat the babies, so a colony rarely grows in a mixed tank. Heavy planting helps some shrimplets survive. The checker above flags the specific clash for your list.

No — two male bettas will fight, often to the death, so keep one male per tank. Females can sometimes be kept in a larger "sorority" group, but it's advanced and can fail. For beginners the rule is simple: one betta per tank.

Stick to small, peaceful nano species in a cycled, planted 10-gallon: assassin snail, cardinal tetra, celestial pearl danio, ember tetra, endler's livebearer, harlequin rasbora, mystery snail, neon tetra. A single betta also suits it. Avoid goldfish, cichlids, larger tetras and most loaches — they need far bigger tanks. Keep shoaling fish in a group of one species rather than one each of many.