What Can I Keep In A One Gallon Tank?

Nano tanks are growing in popularity. However, the misconception here is that they are easier to maintain, which might not be the case. Read here to know the why a larger tank is easier to maintain.

If you want to set up a one gallon tank, it is best to breed something that can survive well in such a small environment. In general, I don’t think any fish is suitable. However, if you can’t afford a bigger tank due to space constraint, see below for my suggested list.

Here is what we think are the best aqua pets for a one gallon tank

  1. Shrimp (ghost or cherry)
  2. Betta Fish
  3. Snails
  4. Hermit Crabs
  5. Plants

Challenges of a one gallon tank

If you have never had a one gallon tank before, here are the challenges that you might not be aware:

  • Any small changes in the tank can lead to huge spikes in water perimeter due to the low volume of water. For example, if you accidentally leave the tank in the sun for too long, the temperature rise will be quick and might kill off the fishes in the tank.
  • Limited accessories. You got less toys to work.  Hence, things that is possible for a large tank might not be doable for the small tank due to lack of suitable tools
  • Work with live plants. Since you might not even have space for a proper filter, you need the live plants to help with maintaining the water ecosystem. This can be a challenge if you never work with live plants before. My suggestion is to work with these: Java Fern, Anubias, Small Swords. They are easy to care for with the only wok being trimming any outgrown leaves.
  • Evaporation:  Remember to always top up water for your one gallon tank, especially if you live in a humid country. The water runs out easily for a low volume and it is easy to forget this.


List of suitable things to keep in a one gallon tank

  1. Ghost shrimps

Shrimps are easy to maintain as they are not as sensitive to water conditions.

However, that does not mean they make uninteresting pets. In fact, shrimps are pretty active in the tank and it is a joy to watch them in action. Some of them, like cherry shrimps, are pretty colorful as well. However, amano shrimps might not be suitable as they can grow into larger sizes.

I suggest you start with ghost shrimps as they are (1) cheaper and (2) do not breed as much due to the parents eating the shrimplets.


  1. Betta

Most folks think it is ok to keep betta fish in a one gallon tank. I personally don’t recommend it but if you really want to have a fish in such a small tank, then betta is your best bet.

First a male betta can grow up to 2 inches, which will be a bit of a squeeze in tank. So, go for a female betta instead as their max size is smaller.

Make sure you change water frequently.

Small tanks gets dirty easily so you need to change water at least 3-4 times a week to be safe. Simply cup the fish before doing the change and proceed according. The good news is that  a small tank should be easier to clean.


  1. Snails

Snails is another safe aquatic pet to keep in a one gallon tank. I know they are not that exciting to watch but they will live comfortably within that space.

The type of snails that are suitable for one gallon tank include ramshorn or malaysian trumpet snails. You can keep 5-8 of them without any problems.

The only thing bad about keeping snails is that they poo a lot so you need to clean the tank frequently.

It is not a bad idea to add a shrimp to go with the snail to make things more interesting.


  1. Hermit Crabs

Hermit crabs is another better alternative to fishes.

They hardly need any maintenance beyond food and cleaning so they are perfect for a small tank. You just need to vacuum or remove their bio waste at least once per week.

Compared to snails, hermit crabs are more lively. Their movement is pretty hilarious especially when they try to get themselves into the shells they found.

If you are not aware, hermit crabs like to bury themselves into any shells they come across.You will laugh out loud watching them getting into the right positions. Sometimes, they just seem so confused.

So, you should definitely add some shells in the tank if you want to see how they react. In addition, Hermit crabs do like to hide so plants will help as well.

In terms of number, having 2-3 hermit crabs should be fine for a one gallon tank.


  1. Plants

You can create a nice mini aquascape with a one gallon tank. I mentioned earlier that plants like Anubias and ferns can work. Basically, these plants grow slowly and wouldn’t over run your small tank.

Another consideration is adding mosses on your rocks. These look very beautiful if done right and wouldn’t take up too much space.

A pure planted tank will remove many issues that small tanks have, namely the lack of proper accessories, frequent water change etc.

All you need for a small planted tank is lights, a small amount of fertizilers and water stability. You don’t need things like Co2 or filters.



One gallon tank is a challenge to keep any fishes. I have seen lists of the Internet that suggest fishes such as betta, guppies,  neon tetras etc. Although they are small fishes, they still need the proper room to swim around. In addition, too small an environment means they can easily get infected with bacteria and such.

Overall, I would avoid keeping any fishes in a one gallon tank. If you like betta, aim for a 5 gallon instead. I have recommend some 5 gallon fish tank here.

It is better to keep some of the other alternatives I have listed above. They will be happy within such a small tank and isn’t that what we want for our aquatic pets?

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