Been growing for 20+ years ... speaking from experience. Not heresay and not paid by anyone. Also not going to argue about it, just offering free advice. Take it or leave it.
Arguing and name calling solves nothing, trust in tested results not word of mouth. Besides none of these lights have what plants crave.... Brawndo the thirst mutilator.
In my opinion, Appears to be burn. Flush and test runoff. Water RO only for a few, if it yellows more quickly hit it with calmag. Don't forget to let those roots dry out once a week or so.
There is a few basic steps to take to test what's going on. Flush with RO and test runoff. Do you have a scope? What are temp spikes reaching? How do the roots look?