The Pool Sentry is used to maintain the water level of a pool, spa or pond automatically and unattended. When the Pool Sentry is removed from the box, it is easily assembled by snapping together two parts and threading in the valve assembly. This requires no tools. It comes with a heavy plastic, sealable bag that you can fill with rocks or pea gravel and use as a weight to hold the unit on the deck. The bag is placed inside the cavity by removing the top cover. It is then attached to a garden hose and the water is turned on. (Shipping the Pool Sentry with the bag empty reduces the weight of the package.)
The water stays on at all times when The Pool Sentry is in the pool. As the float drops, the water turns on. When the float reaches its highest point, the water shuts off. It works very similarly to the float valve in a toilet tank. You can adjust the float to any desired level (usually a point halfway on the tile line or skimmer).
Because the hose is under constant water pressure, it is recommended that the customer uses a heavy-duty, reinforced hose. (The hose pictured is sold separately.) It is guaranteed to 200 psi working pressure and 750 psi burst strength.