Choosing fish There are a long row of fishes that are suitable for your first aquarium. Which fishes to choose is up to your preferences but there are some basic rules to follow.
• Make sure all you fishes have the same preferences regarding water temperature, pH levels, water hardness etc. Fishes will only thrive in certain water conditions. These preferred conditions varies from species to species and you should only keep species with similar demands in the same aquarium since this is the only way to be able to meat the demands of all your fishes in one aquarium.
• Make sure that you only keep fishes with similar temperament together. If you keep more aggressive fishes with more timid fishes the timid fishes risks to be pushed aside. This can result in that they dont get enough food or become stressed which can cause diseases and ultimately kill your fishes. There is also a risk that the more aggressive fishes kill the more timid ones.
• Dont keep to large fishes in your aquarium. This is a common mistake. Fish should not be kept in aquarium that are too small and restrict their movement. Find out if a fish can live as an adult in your aquarium before you buy it. Many usual beginners fishes grow too large for most aquariums.
• Dont keep to many fishes in the same aquarium. There is no easy answer to how many fishes you can keep in the same aquarium. Since different fish species pollutes the water differently. There is however a basic rule of thumb that says that you can have one small fish, under 2 inches/ 5cm for each litre of water. This is however just a basic rule of thumb and shouldnt be considered a fact, the true amount of fish you can keep in aquarium can be much lower or much higher then this rule suggest depending on which fishes you keep.
You can ask in your local fish store to hear which fishes they recommend for your aquarium. You should however always find out more information about a fish before you buy it. There are a number of good books for beginners that can help you decide which fishes to get.
Many barbs, tetras, gouramis and livebearers make good beginner fishes.