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The Best Fish For A 7 Gallon Tank!

As the surge of people getting into the fish keeping hobby continues to increase and the number of great, cheap 7 gallon fish tanks on the market being a great entry-level option for the majority of people, it really is easy to see why we get so many people asking for recommendations of fish for a 7 gallon tank each month.

There is a ton of poor information on social media offered to people asking for fish recommendations for their 7 gallon tank so we wanted to publish our own article going over our own fish recommendations.

Our hope is that we will be able to help as many of our readers as possible choose suitable fish species for such a small tank that will not only keep the tank interesting with colorful, lively fish but also ensure that the actual fish in the tank is happy and has a good quality of life.

Many of the fish recommendations that we see from people on social media for a 7 gallon aquarium simply should never be kept in a tank so small and the fish will end up miserable and unhappy.

All of the featured fish below has been kept in a 7 gallon fish tank without issue but we would always recommend that you go with a “long” design rather than a “high” design for all of our recommendations in our list below.

In addition to that, of the species we have below will also do well in larger tanks making it easy to transfer them in the future if you do upgrade your tank as the decent 20 gallon tanks are cheaper than ever.

Betta Fish

Betta fish have the be the default recommendation for a fish in a 7 gallon tank with betta fish probably being the most commonly kept fish in such small tanks.

Their beautiful colors and patterns keep them popular and the rare colored betta fish are much cheaper than they used to be due to more and more people starting to try their hand at breeding them.

We would only recommend that you keep a single male betta fish in a 7 gallon aquarium due to their higher than average levels of aggression.

Technically you could keep two female betta fish in a 7 gallon aquarium but it is a little bit small for a betta sorority and we usually recommend that you use a 10 gallon tank as an absolute minimum for a betta fish sorority tank.

Pea Puffer

An excellent fish for a 7 gallon aquarium is the Indian pea puffer with the fish seeing a large increase in its popularity in recent years due to its unique color combination and pattern.

The Indian pea puffer is a relatively cute looking fish too and although it may look cute, once they reach adulthood, they really can end up being aggressive to their tank mates so it will usually be a solo occupant of a smaller tank like a 7 gallon aquarium.

One thing that we have seen people do with their Indian pea puffer tanks is to add the rarer and more unique looking snails to the tank as a way to control the algae build up and add other pets to the tank.

The purple, blue or black mystery snails are a great option for this due to their unique colors catching the eye and helping to keep your tank interesting without causing problems with aggression in your Indian pea puffer.

Chili Rasboras

Chilli Rasboras really are an underrated fish for smaller tanks and their bright colors really do help to catch the eye.

Considering their unique looks and bright colors, they are one of the cheaper options on the list that catch the eye making them a great option for a 7 gallon aquarium.

There are a number of variants of the chili rasbora these days too with their normal dark red color being standard but orange and yellow variants being available on the market too but their price tags are a little high due to being harder to find.

Celestial Pearl Danios

Although Celestial Pearl Danios are not as popular as some of the other fish species on our list, a couple of them can do well in a small 7 gallon tank making Celestial Pearl Danios a great option for your 7 gallon tank.

They have a relatively unique pattern and color combination too with the fish being pretty cheap due to not being such a popular option allowing you to get them at a much more budget friendly price than the other recommendations on our list.


Guppies are another great option for a 7 gallon tank and although guppies did fall out of popularity for a while, they are starting to see an increase in the number of people keeping them.

This is largely due to the work of the guppy breeding community working hard to come up with some rare and unique looking guppy colors like the metallic gold guppy and the black light saber guppy but regular guppies can work well too.


Although they are not fish, the popularity of cherry shrimp or neon yellow shrimp are becoming increasingly popular in smaller tanks like 7 gallon aquariums and below.

They are easy to care for and surprisingly active too with there being plenty of videos of them on YouTube showing just how active these shrimp can be in your tank helping to dismiss the old belief that pet shrimp are boring.


Although tetras are a great option for smaller fish, the majority of tetra species need a minimum aquarium size of 10 gallons to give them enough space to school properly.

That said, ruby tetras can do well in a 7 gallon tank but they do tend to be difficult to find in North America and Europe due to the other species of tetra being far more popular in these regions.


That brings our article going over the best fish for a 7 gallon tank to an end. We hope that we have been able to help as many of our readers as possible better identify the fish that they should be looking to keep in their smaller tanks. All of the options above can work well with many of them being colourful and active fish to help draw the eye when watching your tank.