Best Fish for a 125 Gallon Tank
Large cichlids, big schools, or a heavily stocked aquascape.
36 species in our database can live in a 125-gallon tank. Here are some stocking ideas.
Schooling fish
Centerpiece & bottom dwellers
Frequently asked questions
What fish can live in a 125 gallon tank?
36 species from our database can live in a 125-gallon tank. This includes 14 schooling species and 15 centerpiece/bottom dwellers.
How many fish can I put in a 125 gallon tank?
Use our stocking calculator to estimate a safe stocking level based on fish size and bioload. A 125-gallon tank gives you 473 liters of volume.
Related resources
Calculate exact stocking for 125 gal →
Species that fit a 125 gallon tank
All 14 species below have a minimum tank size of 125 gallons or less. Remember that minimum group size is part of the calculation — a shoaling species needs room for the whole group, not one fish.
| Species | Adult size | Min tank | Group | Temperature |
|---|---|---|---|---|
| Common Goldfish | 10.0″ | 40 gal | 1+ | 60–74°F |
| Discus | 8.0″ | 55 gal | 5+ | 82–88°F |
| Angelfish | 6.0″ | 29 gal | 5+ | 76–84°F |
| Swordtail | 5.5″ | 20 gal | 3+ | 72–82°F |
| Bristlenose Pleco | 5.0″ | 29 gal | 1+ | 73–81°F |
| Pearl Gourami | 4.5″ | 30 gal | 1+ | 77–82°F |
| Kribensis | 4.0″ | 20 gal | 1+ | 75–82°F |
| Kuhli Loach | 4.0″ | 20 gal | 5+ | 75–86°F |
| Molly | 4.0″ | 20 gal | 3+ | 72–82°F |
| Dwarf Gourami | 3.5″ | 10 gal | 1+ | 72–82°F |
| Apistogramma | 3.0″ | 20 gal | 1+ | 75–83°F |
| Bolivian Ram | 3.0″ | 20 gal | 1+ | 72–79°F |
| Tiger Barb | 3.0″ | 20 gal | 8+ | 74–82°F |
| Betta | 2.5″ | 5 gal | 1+ | 76–82°F |
125 gallon tank FAQ
How many fish can I keep in a 125 gallon tank?
It depends on the species. As a guide, a 125-gallon tank comfortably supports a full community of three to four species. Use the stocking calculator for a specific plan.
Does a 125 gallon tank need a filter and heater?
A filter, always — it houses the bacteria that process fish waste. A heater is needed unless you keep coldwater species; see fish that do not need a heater.
How often should I change the water in a 125 gallon tank?
25–30% weekly, which is about 35 gallons. Consistency matters more than volume.