By the same token frame aquariums can not move, do not sink first completely water. The aquarium usually contain several species of fish. When selecting fish for sharing content, you must first pay attention to that match the requirements of the conditions of their housing and feeding. Dell is often quoted as being for or against this. Than more different kinds combine in a tank, the harder it is to create optimum conditions for each fish. However, the majority of fish species live in a fairly wide range of conditions, especially as they can to a large extent adapt to conditions other than optimum. For example, the neon can be kept in water with temperatures ranging from 16 to 28-30th at the rigidity of 1 to 20 at the same time, these and many other fish lose their ability to multiply after detention in conditions not suitable for them.
When purchasing fish, it is necessary to pay attention to their age. If there are no special considerations, such as the need for emergency landing on the spawning, it is better to take young fish, as they are better acclimatized to the new usloviyah.V large party of young fish is best to choose the larger specimens, and adult specimens are medium in size. Should not take small "overextended" the fish. Exception are those cases where it is difficult to distinguish between the floor and when they choose a few of the largest and the smallest number of instances of young fish to increase the likelihood of obtaining an equal ratio of fish of both sexes, as it has place, for example, the selection of angelfish and some other cichlids.