How Many Fish In A 10 Gallon Tank & Ideal Options | Aquascape Addiction

How Many Fish In A 10 Gallon Tank & Ideal Options

Wondering how many fish you can have in a 10 gallon fish tank? this post will help, we cover some important points as well as some great suggestions to get you started with.

How Many Fish In A 10 Gallon Tank & Ideal Options

How many fish can I have in a 10 gallon fish tank is a common question among aquarium newcomers though it's quite an open question where there is not one definitive answer as it depends on a lot of different factors like the type of fish and size. Let's cover this question in a bit more detail and we will also give some suggestions on what we think are well suited for a 10 gallon aquarium.

How Many Fish Can I Have In A 10 Gallon Tank?

Generally speaking, you can put a few larger fish, some medium fish, and quite a few small fish. As long as they all have enough room to move around, there is no real set number as to how many fish you can put in a 10 gallon tank. 10 gallons, or around 40 liters, is not a very big tank and is considered to be quite small. (We have covered our favorite 10 gallon tanks on this post here).

The real question here is what kind of fish you can stock up in your 10 gallon tank. The number is something that you can really only determine from seeing it. However, that being said, a general rule of thumb is that you can have up to 2 or even 3 smaller fish for every gallon of water.

This does of course depend on the size of the fish. A larger fish might need up to 2 or 3 gallons of water all for itself. The trick here, when wanting to add multiple fish into a 10 gallon tank is to add mostly smaller fish because it means that you can add more of them. For this reason, we have a list of the different types of fish which are suitable to have in a 10 gallon tank, especially ones that can live together.

What Kinds Of Fish Are Ideal For A 10 Gallon Community Tank?

There are several different fish which you can comfortably add into a 10 gallon tank and have them living in unison. Remember that you can’t add a ton of all of these fish into your tank because there are spatial requirements. Keep in mind that two small fish should have one gallon of water, and one larger fish should have at least a gallon for itself. The math is up to you to do. We have compared 10 gallon and 20 gallon tanks on this post and also lighting on this post.

Mosquito Rasbora

These are fairly peaceful fish, they are very tiny, like extremely small, and they like to live in schools of 7 or 8 at least. 8 of these things could easily survive in 2 or 3 gallons of water.

Least Killfish

These are pretty much the same in terms of size, attitude, and spatial requirements as the mosquito rasbora.

Pygmy Corydora

This is one of the only types of corydoras which remains fairly small. 2 or 3 gallons of water can easily support up to 5 or 6 of these.

Betta Fish

A betta fish will make a great addition to a community tank. They will usually get along fine with other fish and one of them only requires a gallon of water or so. Remember, bettas are aggressive towards one another, so you can only have one betta fish in the 10 gallon tank.


These fish don’t grow very large, they do well in groups between 4 and 6 in number, and they are actually great algae eaters. 6 of these can easily be supported by just a couple gallons.

Scarlet Badi

These are feisty, small, and colorful fish. They will do well in pairs or on their own. 2 or 3 gallons of water is way more than enough for a pair of these.

Honey Gourami

Honey Gourami don’t grow to be more than roughly an inch in length, so you can easily add one to a 10 gallon tank. A gallon is more than enough to support one of these guys. They can be aggressive towards one another, so never keep more than one honey gourami in the same tank.

What Kinds Of Fish Are Not Ideal For A 10 Gallon Community Tank

There are a few different fish which are definitely not ideal to house in a 10 gallon tank, let alone in a community along with other species of fish. Here are some of the fish you should avoid putting in your 10 gallon tank along with other fish.

Fancy Goldfish

A lot of people ask this question "how many fancy goldfish can you have in a 10 gallon tank?" and the correct answer is none and here is why. These things can grow up to a foot in length or even larger. A fancy goldfish along needs about 15 to 20 gallons of water for itself, it's not fair on the fish to put it in anything smaller.

Normal Goldfish

These can also grow quite large and are only suitable for larger aquariums or ponds. Sometimes they don’t get along with other fish too well.

Tetra Fish

These are schooling fish, which means that they like to live in groups of anywhere between 10 and 40 fish. These things are already of a decent size and a school of them needs a whole lot of room. A 10 gallon tank will not be suitable for a school of tetras, plus one tetra will most likely not survive on its own.


Danios are very active and quite large too. They need much more room than a 10 gallon community tank can provide.


These simply grow far too large for a 10 gallon tank, let alone a community tank with other fish.

Molly & Guppy

Both of these fish species grow too large to adequately be housed in a 10 gallon community tank.

Other Possible Additions

Besides fish, there are a few other options in terms of animals that you can house in your 10 gallon tank along with some of the fish we talked about above.


The really tricky part here is making the calculations. You have to make sure that all of the fish and creatures in your 10 gallon tank have enough room to survive and thrive without jeopardizing each other. Doing the math will take some work, but it is definitely rewarding.

If you are thinking of getting your kids an aquarium then you might might find this article helpful.