How to Learn Right Amount of Fish to Place in a Fish Tank

Before you begin, you need to decide whether you want a salt or fresh water fish tank. Once you’ve gotten your fish tank set up, you want to get the right amount of fish.

Difficulty: Moderate

Instructions

1. Check the size of your tank. The right amount of fish that you can put in your fish tank depends on the size of your fish tank. The rule of thumb is 1 inch of fish per gallon. Therefore, if you have a 20-gallon fish tank you could have 20 inches of fish.

2. Go to your pet store and look at the fish they have on display. Decide what fish you would like to buy by their looks, color or activity level.

3. Note the signs that the store posts on the tanks. Each sign tells you about the fish--what they are, the type of food they eat, where they swim and their size at full growth.

4. Pay the most attention to the size the fish can achieve. Most pet stores stock very young fish. Therefore, you want to be sure that when the fish are adults they will still fit in your fish tank.

5. Decide on the fish you want to buy. If you decide to buy schooling or community fish, you should buy at least three of them at the same time. Therefore, if you have a 20-gallon tank and you buy three fish that have a potential to reach 3 inches each that counts for 9 inches of the fish that you can add to your fish tank.

6. Buy fish that swim at different levels of the fish tank. For example, danios and hatchet fish swim at the top of the tank, tetras and angels swim in the middle of the tank and catfish and Cory like the bottom of the tank. You also need to consider whether the fish are compatible with each other.

Tips & Warnings

• When calculating how many fish to add to your tank, consider the other things in your tank, such as gravel and decorations.
• You don’t have to add all the fish at one time.
• Pet stores usually have signs posting what type the fish is such as community, aggressive and semi-aggressive.