Have an in ground sprinkler system fed by a pump. Have a fine screen filter but the water sometimes has a bit of fine sediment that makes it through. The system has been in over 10 years and has been fairly trouble free. I have a few zone valves that feed hose connections. Recently I set up a couple hose sprinklers for some areas I reseeded and have had some trouble with the sprinkler screens plugging with small flakes. I am thinking the flakes are small bits of sediment that coated the inside of the pipes and they flaked off, maybe during the winter when the lines were blown out and empty. Does that seem like a reasonable cause? Any suggestions about what to do about it (other than clean the screens several times - it does seem to be limited)?