I just installed a 1 zone with 7 Hunter pgp rotors. I may be pushing it with 7 heads but the distance is still only about 60% of what I am used to seeing with these heads. My employee and I held down two of the heads to see if this would help with the pressure and it didnt so I think I may have a flow problem. I cut into a 3/4" galvanized line with a compression tee about 2 foot off the house meter. Then went through a 1" PVC "check valve" then into a 1" shut off ball valve and then into my 1" irrigation valve, all within 15 ft of the meter. FRom the rotor heads back I have 20 ft of 1/2 " then 10 ft of 3/4" which runs into my main line which is 20ft of 1" pipe back the irrigation valve. Maybe I should not have used 1/2 pipe from the heads? I am thinking the 20 ft. of 1/2" pipe may be reducing my flow but I have done this before with no problems. Tomorrow I am going to check the "pvc check valve". I may replace it with 1" brass check valve which looks a a hole lot smaller and seems to have less resistence on the springs. Maybe this will help out my flow. If this doesnt work I may have to fudge and move heads around because I am going to have a few bad dry spots. I also noticed that the inside of the 1" ball valve looks like a 3/4 opening. Could this be causing a drop in flow? Maybe I could use a 1 1/4" ball valve and reduce down on both sides to 1". I am just baffled. I have been racking my brain to try and figure out whats the problem. Can any of you guys shed some light on what may be causing the problem?