9/23/2016 8:09 PM
Yes, had that problem and other aquatic issues which plugged up irrigation heads/ valves frequently each year in the early spring/summer in the southwest. Depending on your climate, that is the optimum time for treatments. Have used potassium permanganate, liquid chlorine, and liquid 30% hydrogen peroxide with success.
Caution....Oxidizers are dangerous
Potassium was by far the easiest for us to use but still must be used with caution. PROBLEM will get worse before getting better. Reason is right now all those little buggers are clinging tight inside your wet well and irrigation pipes. Once they start dying brother be prepared to flush your lines a lot. Your pump station must have a wet well, block irrigation/ valve in head slightly different procedures and it helps tremendously if you have larger 2" blow offs to day light or a lake on your irrigation system at the farthest parts from the pump station.
1. 3-5 pails of potassium permanganate (depends on size of irrigation system)
2. goggles, gloves and mask
3. Have your irrigation guy start a few heads close to the station, start scooping or pouring powder in wet well and wait for purple water to come out of sprinklers, turn off those sprinklers and move to the next block/row/ or irrigation loop.
4. Keep scooping and have the irrigator keep going (make sure that he runs water until purple water at each station) before progressing Hole by Hole out to the farthest points of the irrigation system.
5. It should be darker than grape kool-aid coming out of the sprinklers in order to be concentrated enough to kill those bast@&ds.
6. Be careful with sprinklers around buildings and white cartpaths this can stain some, not quite like iron but similar.
7. Continue until entire irrigation system is purple koolaid, let set in mainlines 24 hours without watering. By this time the chemical should be brown or light purple in color. The potassium turns brown when you have plenty of organic matter in your water, it oxidizes everything. If you have blow offs use them to purge some water and dead clam shells out at the same time. If not just irrigate normal (micronutrient at very low levels) at night but be prepared to flush and clean, flush and clean sprinklers. Depending on how bad clam or snail population levels are it might take a few treatments. Once a week or every two, three whatever you can till your back to minimal problems. FLUSH FLUSH BABY, Flush flush BABY oh wait its ICE ICE Baby!
Repeat yearly BEFORE the problem normal shows up.
Good luck David