@rraisley - I know this post is several years old but wanted to say thank you for your detailed thoughts on proper watering setup. I have spent so much time calibrating, configuring, doing catch cup tests (so many times over the years), root measuring, mason jar testing, changing my monthly crop coefficient numbers, etc…. and my lawn still turns brownish in the summer. I have tall fescue and I know the Southern California summers are brutal but I was so focused on everything being accurate and assumed the system would water correctly.
I have always had a hard time justifying changing one of my controller’s variables to make my system water longer when I knew they were all setup correctly. I know how much water my zones put down. I know my soil type. I know my root depth. I know my lawn type, etc….
Your recommendation of changing the crop coefficient is genius. It made me rethink things. I have always assumed the 12 month crop coefficient recommendations that are on the internet were accurate. I guess they are more a guideline and they could be wrong. So I took your recommendation and bumped up the recommended number for September by 10%. Time will tell and it might be too late for this summer but thanks for pushing me outside of the box.