Posted by Chris Lewis ·
A "community tank" only works if you pick fish that want the same water and won't bully (or eat) each other. Here's a reliable starting palette for a ~20–29 gallon.
Schoolers (the movement and color). Most small tetras (ember, rummynose, neon — once your tank is mature), harlequin rasboras, and celestial pearl danios do best in groups of 6 or more. A school of six is calmer and healthier than two or three, which tend to get nippy.
A centerpiece. A honey or pearl gourami, or a single male betta in the right setup, gives the tank a focal point. (Skip aggressive cichlids and fin-nippers like tiger barbs in a peaceful community.)
The cleanup crew / bottom. Corydoras catfish are peaceful and love company — keep 6+. Kuhli loaches, otocinclus (in mature tanks, for algae), and nerite snails round out the bottom without trouble.
The rules that keep the peace: match temperature and pH needs across everyone; school the schoolers; give territorial fish line-of-sight breaks with plants and hardscape; and don't overstock — crowding causes most aggression. Run the wishlist through the Tank Builder first; it flags temperament clashes and bioload before you buy.
Your turn: share your current stock list and tank size and we'll spot any clashes — or tell us your dream centerpiece and we'll build a peaceful community around it.