Aquarium Fish

Any Fish You Wish

Now comes the fun part - selecting your fish. Add two fish every two weeks to your tank. This gives the good bacteria time to grow in the tank. Your tank needs good bacteria to protect your fish from harmful waste. Check with the pet store clerk to make sure that the fish you choose will all live together peacefully. Some fish are considered aggressive and will cause trouble in a tank with peaceful fish.

Be careful with the number of fish you put in your aquarium. You do not want to overcrowd them. About 16 fish will be happy and comfortable in a 20-gallon tank with several plants and decorations. The general rule is one, one-inch fish per gallon of water that you put into the tank. Remember that your plants and landscaping materials also take up space.

Be aware that there are many considerations to mixing fish together in a tank including the size of the fish, the strata (or level) of the tank they swim in, and if they prefer to be in schools or the only species of it's kind in the tank. Aquarium fish generally fall into one of four categories. They are classified as either non-aggressive, semi-aggressive, aggressive or goldfish.

Here is a sample list of fish that will live together peacefully in a 20-gallon aquarium. They all live at different water depths within the tank. These fish will bring lots of excitement to your aquarium with their bright colors and different shapes!

Male and female sunset platy
A pair of rosy barbs
Four bronze corydoras (catfish)
Male and female dwarf gourami
Four zebra danios
One plecostomus (algae-eater)