Hello, I am having some problems in my veg cycle. I am using a top drip recirculating system, House and Garden nutes (Aqua Flakes A&B, since it is a recirculating system), and coco fiber as the medium. Everything was going great for about 2 weeks, and now they have stopped growing all together. I thought it might be a calcium or magnesium lock out, so I flushed and added Cal-Mag to the water resovoir. They seemed like they were doing better, but when I checked them out today they look terrible. Most of the yellowing is occurring on the newer leaf sets. Here is a pic. I am at a loss, and any help would be sincerely appreciated. Thank you for your time.
I was actually told that this resembles severe heat stress.. I've personally never seen heat stress that looked like this.. Comments anyone?
Looks a lot like a Nitro burn. Did you boost nute strength at some point when they still looked good? Place to start would be to flush 'em thoroughly with PH adjusted water alone and let 'em dry out. Give it time and watch the newest growth. The yellow leaves won't recover, and it takes time to see improvement. General rule of thumb with nutes and cannabis is less is more. And some strains can be very touchy with nutes while others thrive under the same conditions. Edit: Instead of a cal or mag def, it may have been too much. And they only temp looked better due to the flush. Then looked worse due to too heavy nutes overall. It's true that heat stress doesn't cause that sort of yellowing.