It’s tempting to select a small aquarium when first beginning with keeping fish. It just makes sense-small tanks look nice, easily fit on a desk or counter, and usually are cheaper than larger tanks. However, those smaller tanks, known as nano aquariums-those under 10 gallons-have some big problems, especially when selecting fish.

The first problem is space. Clearly, your choice of fish will be much restricted in an intimate tank size since only a few species can really flourish in such a small space. The key word here is “thrive,” not just “survive.” Many fish can survive in a 5-gallon tank, but they may not be healthy, nor necessarily be happy. Some fish need more swimming space, and others need more individuals to feel safe and stress-free.

It doesn’t necessarily mean it should be in a small tank because a fish can thrive in that kind of setting. A good fish owner is always trying to make a place where his or her fish will be comfortable and happy, not just survive. So which of the fishes are suitable for your 5-gallon tank? Let’s take a look at some choices!