How Many Fish Can Be In A 10 Gallon Tank

How Many Fish Can Be In A 10 Gallon Tank

If you’re stocking an aquarium and just getting started, you might want to opt for a small tank so that you don’t get overwhelmed before you’ve even begun. A 10 gallon tank can be good for beginners, but you need to know how many fish can survive and thrive in this sort of space.

How many fish can be in a 10 gallon tank will depend heavily on the kind of fish you choose. If you select very small fish, you can add about 1 per gallon of water. More than this could cause overcrowding, waste issues, and an unhealthy tank environment. It’s better to have too few fish than too many.

We’re going to use this article to explore what sort of fish you can keep in a 10 gallon tank and how to set up your tank so that the fish are happy and have enough space.

What Fish Do Well In A 10 Gallon Tank?

A 10 gallon tank is generally considered a small space, so you will need to select fish that are small themselves. There are many different options, but it’s a good idea to check multiple sources for guides on how much space your fish will need. A lot of sources will tell you much smaller sizes than the fish actually require, so be cautious and do thorough research.

Fish that will do well in a 10 gallon tank include things like:

  • Ember tetras
  • Siamese fighting fish
  • Pygmy corydoras
  • Guppies
  • Neon tetras
  • Betta fish
  • Cory catfish
  • Japanese rice fish
  • Chili rasbora
  • Zebra danio
  • Freshwater pea puffer
  • Celestial pearl danio
  • Dwarf gourami
  • White cloud minnow

All of these should be happy in a 10 gallon tank, provided you do not add more fish than the tank can handle. This will generally be 10 or fewer. Another guide that some people use is 1 inch of fish per gallon of water. This might help you to determine whether you are overstocking your tank or not.

Overstocking can have major implications for the health of your fish, the state of the water, the stress levels, and more – so be wary and err on the side of understocking where possible.

Is A 10 Gallon Tank Big Enough?

A 10 gallon tank is big enough for some small species of fish, but it is not big enough for any medium or large fish. You will need to think about the space the fish have, and choose your species accordingly if you only have a 10 gallon tank. You will also need to be very aware of how aggressive your fish are likely to be.

It’s important to think about several different factors when considering your fish and whether they will have enough space. One of the first factors is the fish’s size and shape. Fish that are larger obviously need more room, but think about the shape of the fish’s body as well as its length. Bulky, rounded fish require larger tanks.

Their typical behavior is another major factor. Some fish are much more active and curious than others, and they need more room. Those that are aggressive and territorial likewise require a good amount of space if they are to thrive.

Some species can only be kept together if they have plenty of room, so this is another thing to be aware of. If you take all these factors into account, you should be able to stock your tank accordingly.

How Big Should A Fish Tank Be For 10 Fish?

This depends heavily on the fish that you wish to keep. If you are keeping minnows, small tetras, or other tiny fish, a 10 gallon tank may be large enough to house 10 fish in total. However, if you want to keep bigger fish, you’ll need significantly more space.

Some fish cannot be housed communally no matter how much space you give them, but otherwise, apply the “one inch of fish per gallon of water” rule and your own common sense about how the fish behave and what they need.

Remember that overcrowding your tank is dangerous and could have a major impact on the fish. It will make it much harder to manage the tank and keep it healthy, so it’s best avoided for your sake as well as for the fish.

Biggest Fish For A 10 Gallon Tank

If you want the largest fish available for a 10 gallon tank, you may struggle. Most fish that are suitable for small tanks are also shoal fish, and will be unhappy if kept alone. That means you’ll probably need to put in several guppies or tetras, even though these aren’t the very largest that can be kept in this size aquarium.

A single dwarf gourami is probably the biggest fish you can keep in a 10 gallon tank without causing the fish to be unhappy. A single betta may also be a good choice, as these fish are happy when solitary, and fairly hardy. However, they are not huge, so you may feel that your tank looks a little empty with just one of these.

How Many Guppies In A 10 Gallon Tank?

If you’d like a small group of guppies instead, you should be able to keep between 5 and 7 in a 10 gallon tank. They get to around 1.5 inches long, so they should still have enough room to swim even if you keep a small group of them.

Don’t add 10 guppies to the tank, because they tend to be a little over 1 inch each, so they need more room than this setup would provide.


If you have a 10 gallon tank, you will need to stock it with care to minimize issues. Choose small shoal fish and do not add more than around 10 small fish at the most. If you want larger fish, bear in mind that you will only be able to have a few, often between 5 and 7, before the tank gets too crowded.