White Widow. 1 plant doing fine, other 2 have this on the leaves. I’ve tried ph adjustment, soil ph showed between 6.1 and 6.5 all around the pot. Runoff PH was a little more eye opening and showed as 5.9, but I figured the Limestone on the bottom might have added to that low reading.
At first I blamed temperature issues because both plants were near an air source. One right next to the air intake the other right in front of the little fan that circulates above the plants. I moved the air intake hose up above the plants, closer to the lights. It made it easier to keep the temperature around the plants themselves steady, but these two still kept browning. I wouldn’t have been so concerned except I started to notice new growth with the same browning. The brown seems to run along the veins and then blobs outward.
Today we flushed the one plant. The other has become a sacrifice to the drying room test. (not bad bud for an immature and sick plant.)
Today I flushed with sledgehammer.
Anything else come to mind guys?
Unusual to intake air from a high portal. Most generally, we draft from the bottom where the coolest air in the room is. This also allow cool ir to come up through the plant, cooling it more effectively.
But,if you found a way that works for you. Good deal.
Cannot wait to hear about your yield. 
Peace
My intake is in the lower portal. The room the tent is in can get really cold by the floor. It’s the silver hose inside the tent that I lifted, so that the cold air has a chance to mix with warmer air before it reaches the plants. I maintain about 77 F inside the tent, away from the lights. Where the light lands is about 85ish.
I have connected a cord to both silver hoses so that I can lift the outer away from the cold floor and get it up in the warmer air above and I can direct the inner to wherever in the tent I want it. At night with no lights I have an electric space heater set to 75 F. At the floor the temp can get as low as 55 F, maybe lower during the coldest part of the night.
Once winter is over, I can simply lower both tubes back to the floor to take advantage of the cooler air near the floor. It’s not perfect, but at least I feel like I’ve got some control.
The HID light is near the higher portal so that the output fan sucks as much of the heat from it as possible. The LED’s don’t seem to make very much difference, perhaps 5 degrees inside the tent.
Well, anyway, like I said, I don’t think the temperature was the culprit this time. I’ll see how she recovers in the next week or so. No drooping or any other symptoms at this point.
The rest of my plants are looking wonderful.
I’m interested in figuring the yield as well.
January…
Awesome; I misunderstood the description. Good idea; Air will definitely warm a bit suing this method. You have good concepts. Good luck.
I have found that occasionally, you get a plant that just does not perform as well as the others. Peace