Like Jim said, check your pressure tank. My neighbor had low pressure and he's problem was the tank. It just needed a little extra air to bring the pressure up to where it needed to be. He did have a 2nd problem, even though the in the house was now fine. He's 2nd problem was 2 folds for watering his lawn. 1st was the bibs used. The builders plumber put ones it that didn't provide enough volume. The 2nd problem he has were his quick connects on his hoses. He put them on to make it easier/quicker to change from a sprinker to a hand nozzle, but he found that the quick connects restricted the water volume also. He's good now. and from what I can tell, he has better water pressure then I do. Then again, I know he's running his pressure tank on the high side.

Thanks Turf- My Dad has a largish compressor with a decent size tank. I am also thinking about adding an in line drain. I will only have one zone buried with 2 or 3 Hunter PGP heads. There is a slight grade over that area. I plan on installing a lateral line drain at the low point. (draining to into a french pit - and my soil is on the sandy side). These drains are closed with a psi >5, when the pressure drops they drain slowly. Here is a link to the drain I have. http://www.sprinkler.com/buy/item/line_drains/4311 Just curious - How deep did you get your pipe and how is it holding up? This question is for Turf or anyone else who made a custon underground system. I think I will only get the pipe 6-8 inches deep.

Good news! the clog is gone... turns out it was just a rock clogging the pipe. Apparently, the moron that installed the system decided to put a 90 degree elbow about a foot and a half away from the last sprinkler... then used "funny pipe" to run the last foot and a half. this involved another 90 degree "funny pipe" fitting then the funny pipe, then another 90 degree "funny pipe" fitting attached to the sprinkler. the rock got caught in that first "funny pipe" fitting... stopping the flow. Anyhow, thanks for the advice!!

It has ten heads on it, as does the other line in that part of the yard -- kind of the far end of how many you want on one line, but I've put low flow heads on them to help. The other line with ten heads pops and this one doesn't. However, I may have just located the problem. I got to thinking that the one consistent issue has been the blow by on the last head on the line. I propped it in the up/open position and tried turning on the water & it popped multiple times with no problem. So, thinking the problem may be the blow by caused by the leak on that head, I replaced the head with a new body I had. After replacing it, the line pops and I was even able to open up the ones I had closed and it still pops. Time will tell . . .