My water tank is water logged and short cycling. I know I need to add air but I don't recall the exact steps and I don't want to damage the system. I think I have to turn off pump.. drain water until the tank is about half full and the air nozzle is above water level... use air pump to add air into tank... Is this correct and if so how much air should be added ( to what pressure )... if incorrect or incomplete.. what's missing or wrong?