BACKGROUND I'm going into my 6th full season on a well for irrigation. Previously the system was on city water and original install was in 2002. I'm not the original owner but judging from the condition of the lawn when we purchased 9 years ago, the previous owners didn't water as much as they should Understandable as the cost of water is why I had a well drilled. I recently expanded my system by splitting a zone and extending coverage for some changes we've made to the landscape. I noticed a brown coating inside some areas of the mainline and laterals when I split the zone but it washed/rubbed out easily and wasn't a "solid coating" in all the pipes. It was very very fine material but I didn't give things a second thought. The well water is actually crystal clear to the eye and odorless. It tested well as part of the initial certification (sorry, can't find the reports). For giggles I filled a ball jar shortly after the initial conversion and set it on the shelf. To this day it is clear except for a bit of what I believe to be lime settling on the bottom. The well has a sand separator that I flush ever other week and it's usually very clean. The main line is 1.25" (blue line in diagram) and the valves are 1" with 1" "zone main" and 3/4" laterals. THE ISSUE Recently, I'm noticing more and more popups either not fully extending and/or not retracting immediately when the zone shuts off. When I go out to do some "spring maintenance" today I can find an original for make/model. I haven't kept any of those previously replaced. For what it's worth, the original timer was a Rain Bird ESP 16-LX Plus, the rotors were primarily Hunter PGP, and all the valves are Rain Bird. QUESTION Is it worth trying to remove and clean the popups or just replace them? I've got 9 popup zones. This picture needs to be updated for the zone split but it's close enough for this discussion. The changes/adjustments I recently made concern Zones 11 and 12 making 2 zones into 3 while adding 5 new heads. This is from the split of zone 8 into 8/9 and addition of 4 heads from 2 years ago.