I installed a rather large drip irrigation system in the Tucson area using mostly flag drip emitters. Our water is very alkaline and very hard, and many of the 1 gph emitters have plugged. I did flush the system out and I don't think it's so much of a problem with dirt. Many of the emitters have deposits on them. I have a lot of emitters and find I need to turn the ends around in an attempt to clean them every few weeks. Some of the emitters won't clean and I need to replace them. I'm checking t...