The most basic thing you should consider before even considering any type of fish is whether you’d like to keep a freshwater or saltwater tank.If you already have a particular fish in mind, then you’ll need to know what type of water it requires.
2. Fish Size
Fish size and tank size don’t always relate to each other. You can never provide too much space, so, but you can provide too little. Consider how big of a fish you’re wanting to have.
3. Tank Size
If you have a set amount of space for a tank, then you may have to choose your fish based on the tank size your space can accommodate.
Some fish are territorial by nature, while others may bully when stressed or in an effort to protect territory.Shy fish are at the other end of the spectrum, but their temperament has a huge impact on their success in a tank with other fish.
5. Tank Compatibility
You need to choose a fish that will be compatible with the type of tank you’re hoping to keep. Tropical tanks, for example, have warm temperatures, while blackwater tanks have low water pH, making them too acidic for some fish.
6. Number of Fish Needed
Some fish need to be kept in groups, but the numbers need to be specific to support healthy group interactions and prevent bullying, like tiger barbs.
7. Tank Mate Compatibility
Not all fish and invertebrates are compatible to be kept together, even if their water and tank requirements are identical. Some fish will eat anything they can fit in their mouths, including tank mates.
8. Plant Considerations
Are you planning to set up an aquarium with live plants in it? You need to carefully choose the fish and plants you’re going to put in your tank if that’s the case.
When selecting a fish, you should take into account the price of your tank setup and your fish. When purchasing many fish of various types for a community tank, the price of fish can add up quickly.