I still think heat is a problem but now that there's more detail and I look at it closer, I think Rusty's right. I think the problem actually is the automated system or whatever you're using to pump in water and nutes. I doubt if that's necessary. Maybe flush with pH adjusted water and let the soil dry out. Just water by hand if possible. This is just a suggestion as I don't know how your system operates but I'm guessing it's getting too much stuff. It's nice to learn something new. Thanks for bringing this to the board.