I just moved into a new home with a Hunter system and I have never had a sprinkler system before. I have adjusted the heads the best I can. I have rotors, spray heads and some smaler heads close to the house that pop up and rotor. What kind of maintenance do I need to do with this system? How do I clean out the screens I here people talk about? Any information tips will help. Maby there is some kind of maintenance kit I can buy. Thank You jimmy