When the water in the pond drops sharply, this will have a corresponding effect on the fish! The good thing has a device called an automatic water switch! What is this thing for? The automatic water switch automatically replenishes pond water only when needed. You don't need to check it from time to time whether it needs to be supplemented. Once it reaches the switch, it will automatically stop pouring water into the pond. Is it convenient? WORK PRINCIPLE When the water level rises to the water-limited line, the Water Level Control Valve wi l l stop supplying water immediately; when the water level drop, the valve will start to supply water automatically. Healthy and environmentally friendly. Withstand 70 C, Anti-UV. Made of durable ABS. Attractive design. There is no need to check the water level. Easy to install: small size, estimated flow rate up to 40 psi 3 gallons per minute, 60 psi 5 gallons per minute The valve replaces the traditional float valve, no electricity, is easy to use, long life, low failure rate, and save water resources. Widely used in: water tanks, water towers, swimming pools, solar energy, toilets, hot water boilers, animal drinking water, air cooling, humidifiers, civil buildings, cooling towers, hot water boilers, steamers, water tanks, water towers, toilets Specification:   Size: Package Contents: 1 x Automatic water level control valve