Oh, I am having my own nute issues.
In my case, while I also moved from soil to the passive-hydro
that is hempy, it was a nute change that lead to some yellowing
that I am dealing with.
It seems that the ProBlend line from Botanicaire is pH buffered
and buffering in a way that handled my tap water well.
I have been moving to some Advanced nutrients (i.e. Kushy Kush)
and I learned, slow and hard, that the pH of the new mix was
chemically pruning my plants (!).
Well, I am checking pH and adjusting now....something I needed to
start doing anyway.
I look forward to good things here!
JD