Float valves are a simple tool to regulate the flow of water inside a hydroponic system. Float valves cut off a water input after the water level of the receiving reservoir has hit a pre-determined level. This works by the float of the float valve rising with the water level, and …then shutting off the valve portion once water hits a certain height. Float valves work best when used in system where a continuous water supply is needed, by the source of the continuous water cannor be easily controller. For example, an RO system that feeds into a 55gal reservoir would need a float valve, as it would otherwise be difficult to time the operation of the RO system. Shop now to find the proper float valve for your needs!