The short answer
Plan a community tank by matching three things across every species: temperament, water parameters and the level of the tank they occupy. Pick fish that are peaceful together, want the same temperature and hardness, and spread across top, middle and bottom so the tank fills out. Start with a centrepiece, add compatible shoals, then a bottom group and a cleanup crew — and stock within what your filter can handle.
The three things that must match
Temperament comes first — never mix aggressive or fin-nipping fish with slow, peaceful or long-finned ones. Water parameters come next: soft-water fish and hard-water livebearers won’t both thrive in the same tank, so group species with similar temperature and pH needs. Finally, use the levels of the tank — surface fish, mid-water shoals and bottom-dwellers — so the community looks balanced and fish aren’t all competing for the same zone.
A simple planning method
- 1. Pick a centrepiece — see what a centrepiece fish is
- 2. Add 1–2 shoals of 6+ mid-water fish like neon tetras or harlequin rasboras
- 3. Add a bottom group such as corydoras or a bristlenose pleco
- 4. Add a cleanup crew — nerite snails or amano shrimp
- 5. Check numbers against your tank and filter
Add each group in stages over a few weeks, not all in one trip.
Before you stock
Cycle the tank first — see how to cycle an aquarium. Work out capacity with how many fish you can keep, choose beginner-friendly species via best community fish for beginners, and match your filter through the aquarium filters hub. New to the hobby? See the best aquariums for beginners.