Betta tank mates

Many male bettas do best alone in a heated, filtered 5–10 gallon tank. Community is a maybe, not a promise. Watch for constant flaring, torn fins, fish pinned in corners, and shrimp that never leave cover. If that shows up, pull the tank mates. The betta keeps the tank.

Cycle first. Add mates only after ammonia and nitrite stay at zero. See how to cycle a fish tank. This page is the tank-mate decision, not a second 10-gallon or 20-gallon stocking essay.

Solo betta, or snails

One male in a planted 5–10 with a heater and gentle filter is a complete plan. Soft flow, resting leaves near the surface, and a lid. That matches the betta care page, the 10-gallon stocking guide, and the 5-gallon stocking guide for the smaller tank.

Nerite snails or a mystery snail are the usual low-drama add-ons. They work the glass and leftover food. They do not compete for midwater. Skip snails if your betta attacks shells on sight; some individuals do.

Adult cherry shrimp sometimes hold their own in a heavily planted tank. Shrimplets get eaten. Treat shrimp as a bonus that may get eaten, not a guaranteed colony next to a male betta.

Calm community in a 20-gallon

A planted 20-gallon (prefer the long) gives room for a short-finned school and a bottom group. Soft flow matters: baffled hang-on-back or a sponge filter, not a blast that pins long fins.

Worked midwater picks: a school of ember tetras, chili rasboras, or celestial pearl danios. Dense plants and broken sight lines cut chasing. For the floor, eight pygmy cories fit next to a school of 10 to 12 of any of the three. Six peppered cories on sand fit only next to a school of 10 chilis. With embers or danios they push a 20 past the calculator's waste limit. Either way, add them only if the betta ignores them. Introduce the school first when you can, then the betta, so the territory is not already claimed by one fish.

Skip long-finned show guppies and other fancy-tail livebearers next to a nippy male. Short-finned, calm fish are the bar. Quarantine new fish before they share water; use how to quarantine new fish.

Female betta sorority

A group of female bettas can live together in a larger planted tank, often 20 gallons or more, with cover and uneven numbers so one fish is not singled out. It still fails often enough that it is not the beginner default. Keep a spare heated tank ready for a bullied female.

Do not mix males into a female group. Do not run a sorority in a bare 10 and hope plants alone fix it. If you want simple, keep one female alone the same way you would keep one male.

Hard nos

Another male betta. Fancy or common goldfish. A common or unlabeled chain-store pleco. Tiger barbs and other known fin-nippers. Most gouramis in a 10, including honey gourami stacked with a male betta. Those pairings fight, foul the water, or both.

Inch-per-gallon does not invent space for a second centerpiece fish. If the betta already owns the midwater, add snails or leave him be.

Watch the first week

Lights on, watch for an hour after you add mates. Flaring once is normal. Hours of chasing, missing scales, shredded fins, or fish that never leave a corner means the match failed. Net the mates out. Do not wait for overnight damage.

Heat stays in the mid-to-upper 70s °F for a tropical betta. Confirm with a separate thermometer, not the heater dial alone. Soft flow and a lid still apply when the tank has company. See the aquarium heater page if the kit skipped one.