10 Best Fish (and non-fish) For A 3-Gallon Tank

best fish for 3 gallon tank

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Taking care of beautiful fish could be a fascinating hobby for some. Certainly, you need some spare surfaces to place your fish’s home. But what if there’s only limited room for them? No worries, limited space doesn’t mean there’s no space at all. In this post, we covered up the best fish for a 3-gallon tank or nano tank or small tank or whatever you name it!

Once you get a small tank or also known as a nano aquarium. There you can keep some tiny fish that don’t require much room. There are some fish options where you can choose from. But before start choosing the fish you want to keep, we’ll tell you some facts you might want to know.

Happily ever after?

These little fish might be able to survive in a 3-gallon tank for a while. But we really recommend you get a bigger tank to house them permanently. Fish thrive best in at least a 5-gallon tank. The bigger the tank, the bigger chance for them to grow. There’s a difference between surviving and thriving, right?

3-Gallon Fish Tank Setup & Caring Tips

Smaller tanks are considerably harder to maintain. But if you’re willing to spend some effort on it, we can give you some tips:

  • Keep a close look at the water parameters. The smaller size makes it easier for changes in water quality and temperature.
  • Use a water filter to prevent bioloads from growing rapidly. Bioloads from your small fish can accumulate and could be dangerous for them.
  • Change the water every week. At least 25% of the water needs to be changed to maintain suitable water quality for the fish.

You’re already well-informed about the 3-gallon tank, so let’s buckle up and check out who could be your tank inhabitants now!

Best Fish (and non-fish) for A 3-Gallon Tank

1. Betta Fish

The male betta is our best fish for 3 gallon tank in this list due to their solitary character.

The first on the list is one of the most popular small freshwater fish. Bettas can be a perfect keep if you have a smaller tank. They grow only up to 3 inches in size. And the plus point, they got eye-catching colors and fins!

They are territorial and not very sociable, so you can only have one betta in your 3-gallon tank. This also provides them enough space to swim around.

Originated from tropical areas, water temperatures between 74-82°F will be best for them. There’s not really special care for them, which is great for beginners aquarists. Bettas are carnivores, so pellets or flake foods will work for them.

2. Tetras

Next up on the list, we got Tetras. They are small enough to live in your 3-gallon tank. They grow up to 1.2 inches on average. In some rare cases, tetras could be as big as 1.5 inches (3 cm).

Tetras are schooling fish, so you can keep them in groups of four or five in one tank. But they would live their best life in bigger schools and tanks. 10 or 20-gallon tanks and groups of six and more are just perfect for them.

Like the bettas, tetras prefer warm water as well. 75-80°F in temperatures and pH ranging from 6.8 and 7.8 will do best for them. Tetras are omnivores and not picky eaters. You can give them tropical flakes, tropical granules, shrimp pellets, and even live or frozen food.

3. Least killifish

best fish for 3 gallon tank

The least killifish, also known as dwarf top-minnows, is the smallest livebearer. They’re also one of the tiniest fish there is!

No wonder since they grow only up to 1 inch long. For your 3-gallon tank, a bit less than a handful of least killifish will do. It is quite easy to take care of them. The least killifish can thrive in various water conditions.

It’s most common to find them in freshwater in their natural habitat. But they can withstand brackish water too. Room temperature water ranging from 68 – 80°F is best for them. But they can survive in slightly higher temperatures, about 50 to 90°F. The best water pH for least killifish is around 6.5 to 8.

Another good news, they eat most fish food. But try to feed them with live food if possible. Mosquito larvae, bloodworms, brine shrimp, wingless fruit flies, and small daphnia are the best dietary for least killifish.

4. Bumblebee goby

best fish for small tank

Another small fish for your 3-gallon tank is the bumblebee goby. These beautiful black and yellow striped fish are stunning and lively. In terms of size, they only reach up to 1.7 inches long. And might even smaller if kept in tanks.

Despite them being peaceful, they can get quite aggressive to each other. So it would be wise to keep just one of them in a tank. Bumblebee goby is probably more famous among expert aquarists. It is because they are quite difficult to handle.

They thrive best in brackish water, but some aquarists successfully keep them in freshwater. Water temperature between 72-84°F with a pH from 7 to 8.5 suits them best.

They eat ravenously and only things that move. So live foods are your only option. If you decided to keep bumblebee goby, blackworms, bloodworms, brine shrimp, daphnia, and mosquito larvae can be your food references.

5. Otocinclus

best fish for 3 gallon tank - Otocinclus

Otocinclus can be a great inhabitant in your small tank since they grow only up to 2 inches maximum.

One thing you need to keep in mind, otos are very social fish. So it’s better to keep them in schools of three or larger. You are only able to keep them temporarily in small tanks. Groups of 10 to 20 in a 20-gallon will be the best place to keep them for the long term.

Otocinclus are pretty easy to take care of. Warm water from 72-82°F with a pH of 6 to 7.5 will do well for otos. They can also help you clean your tank by feeding on the algae. If the algae are not enough, you can feed them blanched veggies as well.

6. Ghost shrimp

If you want to add some varieties to your tank, consider getting ghost shrimp. They can be kept as tank buddies for your little fish.

These little shrimps grow up to 1.5 inches on average. It’s better to keep them in groups, but keeping them alone is also fine. Not only they are aesthetically pleasing to look at, but they’re also incredibly low-maintenance.

Ghost shrimps eat almost everything you give them. You can feed these little friends flakes, pellets, leftover foods, and even the algae in your tank.

Tropical water condition is best for the ghost shrimps. Water temperatures ranging from 65-82°F with a pH of 7 to 7.8 would be ideal for them.

7. Snails

Another species you can put in the tank beside small fish. Snails are quite tiny, so they don’t need much room.

Besides, they only mind their own business. It means they will make good tank companions if you keep other creatures in your tank. But you gotta keep your eyes on them. If they see a chance to flee away, they will.

No special care is required to keep snails. They eat the dying plants in your tank or leftover foods. If there isn’t any, you can feed them algae wafers, fish flakes, pellets, and bottom feeder tablets.

Water conditions depend on the type of snail that you have. It’s better to discuss it first with the breeder before getting them.

8. White cloud minnows

best fish for nano aquarium

White cloud minnows are rare and considered nearly extinct, apparently. But due to their small size, they fit here on the list and in your 3-gallon tank. The adult can grow around 1.5 inches long.

White cloud minnows are peaceful, hardy, and low-maintenance. They’re schooling fish, so they are better kept in groups and only with their own groups. But other small tropical fish is fine as well.

As for the water conditions, a warm temperature at around 72°F and a pH of 6 to 8 is ideal for them.

The white cloud minnows are omnivores. But they prefer live foods such as bloodworms, fish fry, algae wafers, brine shrimp, daphnia, and mosquito larvae. You can feed them boiled green veggies too!

9. Asian stone catfish

Best Fish For A 3-Gallon Tank

This type of fish is not as bright and pretty as the others on this list. They are dull, dark-colored, and only active at night. However, their dullness is offset by the unique whiskers they have.

They are also small enough to live in your 3-gallon aquarium. The adult will grow to about 1 inch long. This catfish can live alone, but keeping them in groups of three or four won’t be a bad idea.

It is best to keep them in cold water. Temperature ranging from 64-75°F would be ideal for these catfish. Their diet is also not very hard as they are not picky eaters. The Asian stone catfish are omnivores. They accept frozen and dried foods.

10. Pygmy gourami

Best Fish (and non-fish) For A 3-Gallon Tank

Pygmy gourami is one cutie that can thrive in your small tank. They have beautiful vibrant colors and can grow up to 1.5 inches on average.

If you want to keep them, make sure your place is quiet and have low, deem light. That’s because the pygmies are sensitive to noises and light. Those things can make their colors fade. Apart from that, they are just low-maintenance fish.

The perfect water conditions for the pygmies are between 77 to 83°F in temperatures, with a pH ranging from 6 to 7.5. The pygmy gouramis are omnivores and not picky. Their diet contains algae-based meals and meaty meals. What a balanced diet!

Final Thoughts

There are always pros and cons in everything. Having a small aquarium will save you some space, but its maintenance could be a bit demanding. However, if you are prepared and dedicated enough to keep it, nothing can stop you! So, which tiny fish do you think suits best for your little tank? Let us know your best fish for a 3-gallon tank in the comment section below!

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