it could be Iron too... Looks vry much like a micronute def., maybe a lockout is causing this. I hv no experience with hydro, just tryin too help.

Good luck
Xavielson Reviewed by Xavielson on . White Rhino, NLxHaze Serious Yellowing! Please Help Hi, Im helping a friend with a setup I made for him. For some reason there is a bad yellowing problem. This problem has been here from very early on as seen in the last photo. Early on we tried to treat this with calmag + I normally don't post much and searched and searched with no results similar. -These were flowered early, like 6-8" then 12.12. -White Rhino x2 & Northern x Haze -GH 3 part Lakewood Formula, on 0,1,2. 1200ppm total 6 gal -Brita Filtered water ph5.4. Could Rating: 5