How to School Fish in an Aquarium

Gazing into an aquarium and watching fish swim in unison -- in "schools" -- can be enjoyable and calming. Some fish instinctively swim in schools to protect themselves from predators. Many fish owners attempt to encourage schooling in their aquariums. To school fish, you should choose one or two species that naturally swim in schools, add the right number of fish and choose a tank that's big enough to promote schooling. Tropical fish experts recommend adding one or two larger fish which may pose a threat to smaller fish and prompt them to school.

Things You'll Need

  • At least six fish of the same schooling-fish species
  • One or two fish that are bigger than your schooling fish
  • Large fish tank
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Instructions

    • 1

      Choose a fish species that's most likely to swim in schools. AquariumFish.net suggests tetras, danios, white clouds, barbs, rainbows, bala sharks and corydoras catfish. A poll on TropicalFishForum.net ranked the best schooling fish (in the following order) as: black, cardinal and glowlight neons; zebras; rummy nose; harlequin rasboras; celebes rainbows; white clouds (golden); lemon tetras; and congo tetras.

    • 2

      Buy at least six fish of the same species. Schooling fish in groups of less than six tend to become anxious, shy and more prone to disease, according to AquaticCommunity.com. Having only two or three schooling fish in a tank may affect their behavior, causing them to hide or even attack or nip at other fish in the tank, according to AquariumFish.net. A large group of the same species is more likely to school (12 or more of the same species is optimal). Fish of any age will school in the proper environment.

    • 3

      Pick a large fish tank. The larger the tank, the more likely fish are to school. Since you'll need at least six fish of a particular species to school, your tank will need to be big enough to accommodate a school of adult-size fish; keep this point in mind if you buy young fish, which will grow over time. The size of the tank you'll need will depend on the number and size of the fish you buy. Experts note that fish will school best in a 30-gallon or larger tank.

    • 4

      Introduce one or two larger fish to the tank. Some fish enthusiasts recommend adding larger fish to the tank to pose a threat to the smaller fish and thus encourage them to school. However, you don't want the larger fish to eat the smaller fish. To help avoid this issue, choose gentler, vegetarian large fish. Some less-aggressive species include bala sharks, cherry barbs, danios, rasboras, corydoras catfish and blue gouramis.