The function of cyst snail in fish tank is to remove algae, but this kind of snail has low algae removal efficiency, rapid reproduction and strong adaptability, so it is generally not to be kept in fish tank, and it is best to clean it out in time after it is found. The shell of this snail is long cylindrical, brittle and thin, and there is a shell on the surface. Generally, it enters the tank with aquatic plants, so it is best to pay attention when buying aquatic plants.