A built-in filter prevents sand or small fish from being sucked in. Keeps the aquarium clean and gives your fish a pleasant living environment. Product Features: Washing sand, changing water, hake excrement, as long as you shake gently, you can do it, it is not only very simple and convenient, but also environmentally friendly, especially you can enjoy the fun of fish farming. Keep your fish healthy. Inlet filter is to prevent fish/sand from being sucked out. Strong suction and large flow rate. The sand washing cylinder allows you to easily take the waste in the sand with water. It can clean and collect in a short time, it is very time-saving, you can adjust the flow rate with the knob as required.