??? (????) ???? ??? ???: ????????? ??? ??????? ?? ???????????? ?????? ???? ????? ??, ????? ???? ?? ???? ???? ???The pH should not be much too higher or too small. A pH of all around 7.5 is sweet. There must be a constant offer of oxygen inside the fish tank. Ammonia and micro organism concentrations should be controlled. It is better to practice Bi