Community tank planner
A community is not “whatever was on sale.” It is peaceful fish that share temperature and pH, in a tank long enough to swim, with a filter that turns the water over. Start with a 20 long.
A mix that actually runs: 10–12 neons or harlequins, 6 corydoras, sand, a hang-on-back you can pack. That is full enough for a first tank. Add a bristlenose later if the gallons are honest. Leave the betta, the shark, and the common pleco at the shop.
- Measure the glass. Nickname gallons are a lie. You want swim length more than height for tetras and corys.
- Pick a school from the list below, then a bottom crew of the same water type. Leave the betta, the shark, and the common pleco out.
- Run compatibility on the whole list at your real gallons.
- Run stocking with adult sizes and your filter GPH. Stay under ~90% if you are new.
- If you want filter watts, bags, and a water-change dose from the same footprint, use the tank planner.
Peaceful freshwater list
These are the fish we treat as community stock. Click through for diet and minimum tank, then add them to the checker.
| Species | Adult | Min tank | Temp | pH | Temperament |
|---|---|---|---|---|---|
 | 1.5" | 10 gal | 70–81°F | 6.0–7.5 | Peaceful |
 | 1.5" | 15 gal | 73–81°F | 5.5–7.5 | Peaceful |
 | 0.8" | 10 gal | 73–84°F | 6.0–7.5 | Peaceful |
 | 2" | 15 gal | 72–81°F | 6.0–7.5 | Peaceful |
 | 2" | 10 gal | 64–75°F | 6.5–7.5 | Peaceful |
 | 1.5" | 10 gal | 60–72°F | 6.5–7.5 | Peaceful |
 | 2" | 5 gal | 72–82°F | 7.0–8.5 | Peaceful |
 | 1.4" | 5 gal | 72–82°F | 7.0–8.3 | Peaceful |
 | 2.5" | 10 gal | 70–80°F | 7.0–8.2 | Peaceful |
 | 4" | 20 gal | 72–82°F | 7.5–8.5 | Peaceful |
 | 5.5" | 20 gal | 65–82°F | 7.0–8.4 | Peaceful |
 | 2" | 15 gal | 74–79°F | 6.0–7.5 | Peaceful |
 | 2.5" | 20 gal | 72–78°F | 6.5–7.5 | Peaceful |
 | 5" | 25 gal | 73–81°F | 6.5–7.5 | Peaceful |
 | 18" | 100 gal | 72–82°F | 6.5–7.5 | Peaceful |
 | 4" | 15 gal | 75–86°F | 5.5–6.5 | Peaceful |
 | 2" | 10 gal | 72–79°F | 6.5–7.5 | Peaceful |
 | 3.5" | 10 gal | 72–82°F | 6.0–7.5 | Peaceful |
 | 4.5" | 30 gal | 77–82°F | 6.0–7.5 | Peaceful |
 | 2" | 10 gal | 72–82°F | 6.0–7.5 | Peaceful |
 | 0.6" | 5 gal | 65–78°F | 6.5–8.0 | Peaceful |
 | 2" | 10 gal | 70–78°F | 6.5–7.5 | Peaceful |
 | 1" | 5 gal | 72–78°F | 7.0–8.0 | Peaceful |
 | 2" | 10 gal | 68–82°F | 7.0–8.0 | Peaceful |