The solenoid works in conjunction with the ATO controller and sensor to allow the flow of RODI water to your sump and when the water level is replenished the sensor will tell the controller to shut off power to the solenoid to close the valve and stop the flow of RODI water. The solenoid uses 1/4" push connect fittings to allow RO tubing to connect quickly.
Note: While hooking a RODI system directly up to an aquarium can be a very simple, and reliable method for replenishing evaporated water there are inherent dangers that come with a direct connection to an endless water supply to your tank. By utilizing a solenoid in conjunction with the Smart ATO systems, you can help decrease the risk of an overflow, but as with all things mechanical or electrical can fail over time. We highly suggest placing a RODI float valve higher than the water level in the sump as a back up if the solenoid or controller is ever to get stuck in the on position.