A 10 gallon fish tank is one of the most common sizes for a fish tank. They’re large enough to hold a large variety of fish while being small enough to fit in nearly any room or setting. With the right filter, a 10 gallon aquarium is fairly low maintenance. That is not to say it’s maintenance-free simply easier to take care of than, say, a 50 gallon tank. 10 gallon fish tank can be used for saltwater or freshwater fish.