Make sure to moniter your ppms....you can put the normal number of ppms and see what it is in the am.....if it's lower....go up. And see how the plants seem. Now mine didn't get curly or yellow but they sure did wilt.

Rhizome that's what I ended up doing and how I found out I was low on ppms because the very first thing I did was dilute the ppms down....and the plant(s) got worse. I started doing daily res changes on the plant with the problem, monitered ppms and finally realized I just wasn't keeping up with the plant's demands.