BROWING ON OLDER GROWTH FAN LEAVES, HEAT/LIGHT STRESS?

Hello fellow growers,

I am new to the forum and would first like to introduce myself to the community with a warm hello and thank you for any and all future engagement.

My og KUSH clones are having a strange and unfamiliar issue. I am finding Browning on older fan leaves. I will prov8de pics. I am my nutrient solution is as follows: AN CONN. A &B GROW @ 550PPM, CALL AT @150-200 PPM, PUREBLEND PRO TEA @ 200PPM, HYGRO, VOODOO,TARANTULA,PIR, AND SM90. Ph@6.0. Growing in coco, using ro water. Temps are usually below 82 f. Humidity 30% all plants under a single 1000 w MH

THIS BROWNING IS THE ONLY ISSUE.

THANKS FIRNTHE HELP

Heat stress often exhibits in leaf curl upwards. If the temps you report are true...it isn't that, IMO.

Everyone goes about this differently....but I suspect that you are simply over-doing it on nutes and may be seeing the first signs of lock out. It looks like some of the plants in the background are doing this in varying stages as well. Remember...the nute companies SELL NUTES. I almost always go lighter than they recommend and adjust upwards if the plants show me they need more. If it were me I'd back off a bit and see where things go. For now....it isn't a serious issue. hopefully only a few leaves will be affected and a bit of time will right the wrong.