How Many Cherry Barbs In A 20 Gallon Tank?

You can keep 4-10 cherry barbs in a 20-gallon tank, and the number will vary due to whether you have other fish species in the tank. Cherry barbs can sometimes get territorial and aggressive if they don’t have enough space, so it is a good idea to ensure that they are not overcrowded.

We will look at the recommended number of cherry barbs for a 20-gallon tank and the recommended minimum size tank for keeping cherry barbs. We will also investigate how different circumstances may require keeping fewer cherry barbs.

How Many Cherry Barbs In A 20 Gallon Tank?

Cherry barbs are a popular tropical fish thanks to their vivid red coloration and relative ease of care.

Cherry barbs are social fish and are happiest and most likely to thrive when they form a school. Fortunately, one does not need many cherry barbs for school, and a minimum of 4 cherry barbs is recommended per tank regardless of size, as this will allow the fish to form a school and be social.

But what does this mean when you are keeping your cherry barbs in a 20-gallon tank? Is there a minimum and a maximum number of fish allowed, or does this not matter?

To determine how many cherry barbs are in a 20-gallon tank, we will need to determine the following:

  • Whether fish can live in a 20-gallon tank
  • The optimal number of cherry barbs in a 20-gallon tank
  • How cherry barbs will react to other fish in a 20-gallon tan

Group of Cherry Barbs in Front of Plants

Can Fish Live In A 20 Gallon Tank?

Different fish have different requirements, and certain species are happy in smaller tanks while others require more space. This is because fish differ; some may be more active and require more room, while others may be more sedentary and can survive with less movement. Some fish are big, and others may be tiny.

Another factor that may influence tank size is whether the fish are social or not. Fish that can survive and prefer living in solitude can often have smaller tanks as they have the entire area to themselves. Fish that require company will need to be placed in larger tanks so that they have enough space as a shoal.

Can Cherry Barbs Survive In A 20 Gallon Tank?

Cherry Barbs are smaller social fish and can live in a 20-gallon tank; in fact, 10 – 20-gallon tanks are about as small a sized tank as is recommended due to the cherry barbs needing to be kept with others of their species as well as due to their need for a reasonable free-swimming area.

Because of this need to keep cherry barbs on their own, there will be a limitation on how many cherry barbs can live in a 20-gallon tank space. And surprisingly, there is a minimum number of cherry barbs as well. Cherry barbs should not be kept as individual fish, even if they may share a tank with other species.

Cherry barbs should be kept with, at a minimum, 4 of their own species. They huddle together for protection and socialization. Even if kept with other species, cherry barbs will still need to be kept with other cherry barbs to survive.

When Are There Too Many Cherry Barbs In A 20 Gallon Tank?

Cherry barbs should optimally be kept in a tank where there is an allowance for 2 to 5 gallons of water per fish. Building on this, the maximum number of cherry barbs for a 20-gallon tank is 5 to 10 fish. The reason for the discrepancy in the numbers is due to 2 factors.

Cherry barbs like lots of foliage in the water so that they have adequate spaces to hide and protected areas to lay eggs. Cherry barbs also require sufficient swimming space as though they may hide in the upper and lower areas of the tank when needed, and they will usually be swimming in the free open areas in the middle of the tank.

Aquatic plants can take up space, so the more plant matter you install in your tank, the less space there will be for your fish, and this will ultimately reduce the number of fish you can keep; this is also due to cherry barbs forming loose schools, so they are more spread out than tight schooling species.

Another factor to consider is that cherry barbs enjoy nibbling on leaves and will often eat away at your aquatic plants, and of course, the more cherry barbs, the more nibbling will happen. For optimal aquatic plant health, there will need to be a limitation to the number of cherry barbs in a tank to ensure that they don’t overgraze the plants available.

Do Cherry Barbs React To Other Species In A 20 Gallon Tank?

Like many fish, cherry barbs are normally quite timid and not generally aggressive and will most commonly swim away and hide either near the surface of plants or near the tank bottom and any rock fixtures that there may be.

Cherry barbs do school together and sometimes become aggressive if there is insufficient space in a tank. If you opt for different fish species, you will need to choose very small and unaggressive fish and possibly reduce the number of cherry barbs.

In a 20-gallon tank, if there are other fish, the maximum number of cherry barbs is 4-6, while if there are no other fish species sharing the tank, you can probably increase the number of cherry barbs to a maximum of 8-10, provided the tank is not too full of aquatic plants.


If you have a 20-gallon tank, then cherry barbs are best kept in schools of up to 10 fish, although less if there are other fish in the tank. Because cherry barbs are schooling fish, you will need at least 4 cherry barbs so that they can form a loose school which will also need sufficient open water space in which to swim.