What Kind of Fish Is Good for a 20-Gallon Tank?

Twenty-gallon aquariums are large enough to host a thriving community of freshwater fish. However, they should be stocked carefully to avoid overcrowding and nitrate buildup.

  1. Small Tetras

    • Cardinal, neon and glowlight tetras are all excellent choice, and their appearances complement each other. A dozen cardinal tetras with a dozen glowlight tetras can look stunning in a 20-gallon tank.

    Zebra Danios

    • These feisty, active fish are available in dozens of varieties, and do well in community tanks if they are given enough room to dart around and "play" with their tankmates.

    Guppies

    • Guppies do well in 20-gallon tanks, especially if there are more females than males. These livebearers are hardy and forgiving, and breed prolifically (whether you want them to or not).

    Corydoras Catfish

    • Also called "cories," corydoras cats are active, schooling catfish that thrive in large tanks. They should be kept in groups of five or more.

    Dwarf Gouramis

    • There are several varieties of dwarf gourami on the market, ranging from three to six inches in adult size. They can do well in small schools, and also thrive in community tanks.