SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Some of you guys may remember my posts from last year about using the ground water underneath my inground pool for irrigation. I paid a guy I know to do the job, because he was willing to "experiment" with the water supply. He installs commercial systems professionally. At any rate, it works great. There are 4 zones, Rain Bird scrubber valves, Hunter I-20 adv heads(all). The water stains everything it gets on, with red mud color. And by the way, I ran the "common" wiers to the valves thru a switch so I can disable them and just run the pump. I use this to water other areas that my system does not cover(yet). I can run this pump for about 3 hours before it runs dry, theres alotta watta down there, but its dirty and it smells a little. Wish I could filter it so it wouldn't stain everything. My transformer, cable box and telco box at the street are reddish brown on one side. This year it seems(unless) I am imagining it, that the water flow from each head is less. I have spots that don't seem to be getting enough water as well. Is it likely that either the valves or heads are getting clogged? How do I clean them?
thanks in adv for any info,
Brent