Pets For 3 Gallon Tank: Which animals could live in a 3 gallon tank?

Pets For 3 Gallon Tank

Keeping Aquatic animals as pet is very interesting, but it could get costly sometimes.

I have read people, especially newbies ask on social media and on forums if they could start their aquarium journey with smaller tanks like the 3 gallon tank.

Although 3 gallon is very small to keep any aquatic animal permanently, but if you are thinking of keeping them temporarily, then this article is for you, as you will learn about the type of water animals you can be able to harbor in such a small tank for the meantime.

Related: Which pets could be kept in a 2 litter tank?

Whatever you do, you should have in mind that I only advise keeping only juvenile and tiny animals in a 3-gallon tank, not adults.

Pets For 3 Gallon Tank

Some suitable animals to keep in a 3 gallon tank are:

Shrimps: Shrimps have many species, some are quiet large and some are very tiny.

It belongs to the crustacean family, and has many species which comes in many sizes.

There are some species that could be comfortably kept in a 3 gallon tank, especially when they are still small like the cherry Shrimps, ghost Shrimps etc.

They are low maintenance pets and would need only filter, heater and substrates/ plants.

They require less care than so many other aquarium pets do.

So partially removing their water per 2 weeks is okay.

Since the tank is very limited, I won’t advise you to keep more than 4, even when they are still tiny, because they too need to move about and be healthy.


Talking about tiny animals to keep in a tiny tank like the 3 gallon tank, then crab is one of them.

Although not all crabs are tiny and could be suitable to be kept in a small tank like this, even when they are still small.

But some species of crabs like the micro Thai etc that are very tiny could be kept in this type of tank, even when they might have grown.

Related: Which aquatic pets could be kept in a 1 liter tank?

Although these types of crab could be kept in such a smaller tank, but there are still limitations, especially on the numbers to keep.

They can be comfortably kept in a 3 gallon tank if the necessary requirements are in place, such as filter, heater, and the replication of their natural environment such as plants, substrates and if possible some suitable aquarium lights.

So keeping a small group of crabs is the ideal, to avoid over crowding the tank, which could become a real problem.

Pygmy Seahorse:

Although Seahorse are known to be very big in size, but this specie of sea horse is very small and tiny.

Pygmy seahorse can only get to 1.5cm or a little bit more in size, making them very suitable for a 3 gallon tank or more.

Just like every other living things, this specie of seahorse needs enough space to swim about too, so keeping not more than 7 of them per 3 gallon is very good for them.

Also they need live plants and substrates too.

African dwarf frog And African clawed frog:

Another good option for a 3 gallon tank is the African dwarf and Clawed Frogs.

These are the smallest species of frogs and could only get to to size of 2.5-3 inches.

Their small size made them a good match for this type of tank because they could perfectly fit into it.

But the question is, how many of this specie of frogs could be kept in this type of tank?

Related: Why is my African Clawed Frog not eating?

Well, I would definitely recommend not keeping more than 4 of these frogs in a 3 gallon tank, so that they could have enough space and also they don’t easily get the water dirty.

Again when I mention African dwarf and Clawed Frogs, what I really have in mind are their juvenile, not their adults, as the adults need enough space to jump about which is very healthy for them.

We all know that frog’s poops are what normally dirty the water, so keeping having only 4 of them and providing filter and cleaning the tank on a weekly basis is the ideal to keeping them in such a small tank.

Again we all know that frogs has the habit of always jumping about, so while keeping them in such a small tank, you need a tight lid to cover the tank too for them not to just out and get lost or die.

Dwarf Crayfish:

Dwarf Crayfish is another good option for this kind of fish tank.

This specie of crayfish could only grow up to an inch or 2, making it one of the smallest aquatic animals.

So they’re perfect match for a 3 gallon tank and would do well in it.

As we all know, Crayfish don’t easily pollute water in anyway, so keeping not more than 5 of this specie in a 3 gallon tank and having in place things like filter, live plants and changing their water twice in a month is very okay.


Another good aquarium animals to keep in such a tank are snails.

Some snails can actually get too big, so they could not actually be classified as small animals in general, but some species are small and dozens of them could fit into this type of tank.

Related: Do mystery snails need a heater ans filter?

Although big snails like the apple snails could fit into this type of tank, but they could not be more than 2-3, depending on their current sizes, in order for them to move about freely.

But smaller snails like the Ramshorn, assassins, etc could be kept in groups in such a tank.

Although they might reproduce very quickly, so I won’t advise keeping more than 5 of them in such a small tank.

Non Aquatic Pets For 3 Gallon tank

We have seen some aquatic animals that could be kept in such a smaller tank, now let’s see the types of non water animals that could be kept in this tank too.


A 3 gallon tank is a complete match for keeping tiny animals such as insects.

There are many type of insects out there that could be kept as pet.

So if you are an insect lover, then buy 3 gallon tank or even smaller tank for them, and they will be very okay in them, for the fact that their natural environment are replicated in the tank.

Baby Lizards:

If you love land animals like lizards, then this type of tank is very okay for raising them up and change it once they become adults.

Although lizards need enough space and sunlight to run about etc So keep only tiny lizards there and replicate the sunlight with a good aquarium light if possible and you will be okay.


If you’re thinking of having spiders, then get them this size of tank and harbor them there, they will be fine, as they don’t require much territories like other animals.

Best Fish For a 3 Gallon Tank

There are some fish that could be kept in this type of tank too. Although I personally don’t recommend keeping adult fish in a small environment, as they need to swim about in order to be healthy.

So keeping juvenile or tiny fish in such a tiny tank and changing the tank once they grow big is the ideal.

So the types of fish you can keep or raise in a 3 gallon tank are: Bettas, Small Barbs, Small tetras, Cory Catfish, Danios, Black Molly, White cloud mountain minnows and Bloodfin tetras.


3 gallon tank is not a waste, you can use them to raise your infant pets and get them nice and large tanks when they are matured or big, as the case maybe.

Don’t in anyway put adult aquarium animal in such a small tank, forget about what some pet stores do or say, just do what is right for the overall health of your pets