The rainbowfish are a beautiful group of fish that are commonly available for aquariums. Most rainbowfish do not develop their coloration until they are mature, usually at about 12 months of age. They also make ideal fish for beginners, as they are tolerant of a wide range of water conditions. This is because they are faced with widely varying water conditions in their natural habitats. Some rainbowfish come from cooler areas and appreciate the same conditions int he aquarium. It is best to try to find out about the requirements of individual species before keeping them; not all rainbowfish like the same conditions. However, generally speaking, most rainbowfish require medium-hard water and a neutral-alkaline pH. The natural environment of these fish is often well-oxygenated, so make sure there is surface movement int he aquarium. Many rainbowfish adapt to most aquarium conditions happily, providing that the environment is well-filtered and regularly maintained. Since Rainbowfish are peaceful creatures they can be kept in community aquariums with other non-aggressive species. Rainbowfish are schooling fish and should be kept in groups. Keeping several males together will also make them develop more vibrant colours since they need to compete with each other for female attention.