Patent ID: 7641791

Claim:
A system for cyclical control of a water characteristic without feedback comprising: a body of water; a circulation line to and from the body of water; a dispenser located in the circulation line; a dispensable material located in the dispenser; a pump for directing water into the circulation line; a valve having an open condition to allow water to flow through the circulation line and a closed condition to prevent water from flowing through the circulation line; a controller, said controller repeatedly generating a signal having a fixed time period with a portion of the fixed time period comprising a valve open signal to open the valve to allow water to flow through the dispenser and a remaining portion of the fixed time period comprising a valve close signal to close the valve to prevent water from flowing through the dispenser to thereby periodically limit the dispensing of the dispensable material into the body of water; a further pump for directing a jet of water into the body of water; and a sensor for determining if an operational time of the further pump exceeds a preset run time, said controller increasing the portion of the period that the valve is in the open condition and decreasing the portion of the period that the valve is the closed condition in response to the sensor determining the operational time of the further pump exceeding the preset run time to thereby increase the rate of dispensing materials into the body of water.