How Many Fish Fit in a 10 Gallon Tank?

When you think about it, a 10-gallon fish tank seems big enough to have a school of any fish you want. However, that is generally not the case. You need to be smart about how you utilize a 10-gallon fish tank and which fish you put inside otherwise you will have a disaster on your hand. When buying a fish tank, we all aim to have a healthy ecosystem in which we raise fish to be healthy and live a long life. In doing this, it is important you keep the size of the fish tank in mind.

Many people make the mistake of putting fish that are bigger in smaller tanks which leads to disaster. It is important you do proper research beforehand to figure out which fish is suitable for smaller tanks.

How to determine how many fish for your fish tank?

There is a general rule to determine how many fish you can fit in any size fish tank. You want to do your research and decide which fish you want to buy first. Then figure out how big the fish generally grows to be. You want to dedicate at least one gallon per inch of a fish. So for example, if your fish as an adult grows to be 2 inches then you can have up to 5 fish in a 10-gallon fish tank. The number of fish completely depends on the type of fish you want in your fish tank.

So, if you want an aquarium at home with a lot of fish then a 10-gallon tank isn’t the best option. We do however have some suggestions of fish you can easily put in your 10-gallon tank.


These little fish grow to about 2 inches as adults so make a wonderful addition to a smaller tank. They tend to be bottom-feeders so don’t mind being in small tanks and actually work well in cleaning up the tank.

Neon Tetra

If you are looking to have a school of fish in your 10-gallon tank then these are a great option. They grow to about 1 inch as an adult so you can easily have around 10 in your tank. These fish like to be with their own kid, so be sure if you are mixing them with any other kind of fish, you get at least 4-5 Neon Tetra in your tank.

Dwarf Gourami

For beginners that don’t want to overcrowd their fish tank, the Dwarf Gourami is a great option. These grow to about 4-5 inches so a pair of them for a 10-gallon fish tank. These make for a beautiful addition to any fish tank with their bright, beautiful colors.

Other fish to consider:

  • Fancy Guppy
  • Better Fish

Fish you shouldn’t put in a 10-gallon tank:

  • Angelfish: aggressive fish which tends to disrupt other ones in smaller tanks
  • Bala Shark: start off small but can grow to about 1 foot long
  • Gourami: too big for a 10 gallon tank