Sea Life

How Many Fish in a 20 Gallon Tank

How Many Fish in a 20 Gallon Tank

A twenty gallon fish is ideal for the people who are experienced in keeping fish as their pets. People who are highly dedicated to fish keeping usually shift from a five gallon small tank to a ten gallon tank and then to a large twenty gallon tank after some time. The reason behind keeping the fish as pets is that it has been medically proven that keeping pet fish in homes and feeding them and taking care of them reduces mental stress, anxiety and depression to a great extent and for these reasons some people find it very convincing to keep fish in their homes.

Talking about the number of fish ideal to be kept in a tank of size almost twenty gallons, there are certain kinds of species that are ideal for the twenty gallon tanks.  The number of fish actually depends on the size of the fish, a large fish occupies much more space than a small one inch fish. Most commonly, in a twenty gallon water tank, the number of medium sized fish that exceed two inches of their size can range from “one to ten”. The number of small one inch fish can range from “one to twenty”. 

Fish Ideal for a Twenty Gallon Tank

Some fish are ideal to be kept in a twenty gallon tank like guppies, platys, otocinclus etc. Guppies and platys normally grow up to the size no larger than two inches. So, the number of these kinds of fish can range up to ten depending on their size. Similarly, the fish that do not exceed one inch of their sizes (like pygmy corydoras, harlequin rasbora, celestial pearl danio, endler’s livebearers and white cloud mountain minnow) can range up to twenty in number. 

Because we are talking about a medium sized twenty gallon tank, so it is not restricted to only the fish that have size as small as only one inch. Some , medium sized fish can also be kept in the tank but the number of those fish will obviously be reduced according to the exact sizes of all the fish.

Care Instructions for a Twenty Gallon Tank

Like all the fish tanks and aquariums, there is proper care needed for the fish to stay happy and healthy. The water will need replacements for sure. There is ammonia produced due to the metabolism of the fish on a regular basis. So, it must be taken care that the amount of ammonia does not exceed a level that becomes life threatening for the fish inside the tank. For this purpose, it is highly recommended to use automatic filters because the water in the tank of the size as large as twenty gallons will be difficult to replace manually after every instance of a certain period of time.

Moreover, when you feed the fish, make sure you do not overfeed them. Overfeeding the fish can lead to some health issues to the fish like stomach bloating. It can also make the environment dirtier for the fish when there will be leftover food spread in the water. The leftover food sometimes remains in the bottom of the tank and this leads to trapped harmful gasses that eventually start moving up with the passage of time.

Benefits of a Twenty Gallon Tank

Not only a twenty gallon tank but it is said about all kinds of the fish tanks that it reduces anxiety in the fish owners as said earlier, there are some more benefits associated with it. The following are some most prominent benefits of keeping a medium sized twenty gallon tank in the house:

  • A twenty gallon tank is considered the medium size that is neither too small nor too large so, for people who have the experience of keeping fish for a certain period of time and want to increase the number of fish in the tank, a medium sized tank is the best option after they leave their small beginner friendly tank rather than moving directly to a large fifty five gallon tank.
  • Although it is important to clean the tank or replace at least half of the water of the tank after a certain period of time, it is not required to clean the tank as much as it is in case of smaller tanks. This is because the water is present in greater quantity as compared to small tanks, so the amount of waste and ammonia present in the water does not pollute the water as frequently as in cases where there is less water.

The Bottom-Line

A twenty gallon fish tank is neither too small nor too large and the number of the fish that can be kept in a large twenty gallon tank depends on the size of the fish. If the fish inside the tank have the size up to only one inch, the number of fish can range up to twenty easily. But if the fish in the tank have the size up to two or three inches, there can be nine to ten fish kept inside the tank.

About the author

Hadia Atiq

A Writer passionate about learning and spreading the knowledge of sea life. I like to spread the knowledge of different types and species of fish and other aquatic creatures.