I have a 4 zone system in the Lake Mary, FL area that is fed by a shallow well/pump. Starting last season, increasing amounts of fine, very white sand began appearing in the areas around the sprinkler heads. I tried removing the heads and purging the lines of the sand, but it doesn't seem to end the problem. It first appeared at one or two of the heads, and now it seems to be at all of them. Also, it's quite a bit of sand. It showed up at first on areas like walks and driveways, but eventually i...
