To calculate fish capacity for any tank size, first find the tank’s actual water volume in liters or gallons, using its shape and subtracting displacement from substrate and…
Stocking & Tank Management
How Many Fish Can You Put in a 30-Gallon Tank?
In a 30-gallon tank, you can usually keep about 12 to 25 small adult fish, but you should stock by adult size, not juvenile count. A conservative ceiling…
Stocking & Tank Management
How Many Fish Can You Put in a 20-Gallon Tank?
You can usually keep about 8–12 small fish in a 20-gallon tank to start, but the real limit depends on adult size, bioload, behavior, and filtration. A 20-gallon…
Stocking & Tank Management
How Many Fish Can You Put in a 10-Gallon Tank?
You can usually keep about 7 to 8 inches of adult small, slim-bodied fish in a 10-gallon tank, not a full 10 inches. That rule is only a…
Stocking & Tank Management
How to Stock a Fish Tank the Right Way
You should stock a fish tank slowly, using each fish’s adult size, shape, and behavior instead of inch-per-gallon rules. Add no more than about 25% of the planned…