Edited by Marin Hale · last reviewed October 29, 2026
A 10-gallon tank (38 L) is the smallest size where a betta can realistically share space. It’s enough for one small group of calm companions, not a full community. Choose one option below, and keep the rest of the tank for plants.
Editor’s examples: judgment calls built on the verdicts below, not computed stocking limits. They assume:
The lightest option: one nerite grazes algae without adding much waste, and bettas almost always ignore it. It's rated Maybe only because of water: nerites need pH 7.2 or higher to protect their shells, while bettas prefer up to 7.5. Test your tap water and aim for 7.2–7.5.
Check this setup in the compatibility checkerEmbers are tiny, calm and short-finned, so they rarely trigger a betta. Six is their minimum group, and they share the betta's warm water.
Check this setup in the compatibility checkerPygmy corydoras stay near the bottom, away from the betta at the surface. They need a group of 8 and soft sand, and should only go into a mature tank.
Check this setup in the compatibility checker| Good match | Ember tetra | No problems found: water, size, fins and temperament all check out. |
| Good match | Pygmy corydoras | No problems found: water, size, fins and temperament all check out. |
| Maybe | Cherry shrimp | Betta fish eat baby shrimp and may pick off adults. Dense plants and moss help a colony survive. |
| Maybe | Zebra nerite snail | pH ranges only just overlap (7.2–7.5), so one of them will be outside its comfort zone if your water drifts. |
| Avoid at this size | Guppy | Needs at least 20 gallons together. In a bigger tank: possible, with care. Male guppies' long, colorful tails look like a rival betta and often trigger attacks, and guppies may nip back. Female guppies in a 20+ gallon planted tank work best. |
| Avoid at this size | Neon tetra | Needs at least 20 gallons together. In a bigger tank: possible, with care. Usually fine with a group of 6+ neons, but stressed neons can nip and some bettas chase them. |
| Avoid | Angelfish | Angelfish grow far larger and are territorial, both claim the upper water, and each has long fins the other may attack. |
| Avoid | Common goldfish | Common goldfish need cool water; betta fish need tropical water. |
| Avoid | Fancy goldfish | Fancy goldfish need cool water; betta fish need tropical water. |
| Avoid | Tiger barb | Tiger barbs nip fins, and betta fish have long fins. |