What is wrong with my leaves?

Hey guys its F4L again. Heres my dilema. Im about 3 or 4 weeks into flower and its been about a week that my plant leaves have gotten brown crispy edges. Ive read that its either neut burn or heat stress.
I had the lights close and forgot to move em up as they flowered. They were at less then 16 inches and i hust recently lobed em back up to 22 to 24 inches depending on where u measure from the colas. Just recently my temos have been gettingbup to 31°C in the tent during lights on as weve had a humidity wave in my area. The night time temps have been 19 to 22. Humidity lihhys out have been 47 to 54 %.
Now ive been using Iguana Huice Organic bloom and grow. Im in flower so im using bloom and it calls for 4mls to 1 liter of water. Ive been doing that sinve the start and each plant got half the mix each. Ive never had s problem all thru veg and half of flower but now its showing somethings up. I cant see it being neut burn as ive beem folowing directions. Could it be heat stress and while my plants recover or how can i make it better?
Thanks in advance. F4l

I had the same thing on one of my girls with the lights about 15" above. Some brownish edges but mostly yellowed/yellowing fans under the light that were very evident around Week 5. The leaves towards the outside of the plant were still green so it had to light burn. 2 weeks ago, I moved the lights to 18" above and turned their intensity down to about 75% power ( ... 2 dimmable blurple LED's ) reducing my wattage from 73 w/sq.ft to 52.5 w/sq. ft. That's a bit more in line with the recommended w/sq.ft. for mylar lined grow tents.

The leaves that were affected by the light stress did green up just a smidge - but not much. The bud itself was a different story. A few days after I made those tweaks, a significant number of new white hairs popped out from inside the bud and over these past 2 weeks began to fill out nicely. All parts of the bud look much chubbier now as they make their final dash to the finish.

So ... what lights are you using?

2x 1000e sunraise led lights. 1 per plant. 2x4c5 tent. For my black rhino, i have the light maxed out and tied to the top frame and the dinamed cbd plus had maybe 6 to 8 inches left to the top.
Thanks for the info staircase. I hooe mine boynve back.
Also i thought u had to wait a week then add the weeks it takes to finish buds. So i thought i was only at 4 weeks but now im at 5 weeks.

Sunraise 1000 LED - 165 true watts / unit. Two of them in a 2 x 4 is perfect as you are in the 40 - 50 w/sq.ft range. You can leave them at full power if you can keep the lights at least 20" above the canopy.

The 560 wall watts in my 2 x 4 (8 sq. ft. grow area) ended up being too intense for this particular SCROG set-up. The next cycle, I am going to lower the SCROG net by 6" so that I can have the lights on full power and prevent light burn. But right now, I am so glad that I chose their dimmable lights.

Day 1 of the flowering begins the first full day your ladies are on the 12/12 cycle.

Thanks staircase i holp since i mobed up my lights they will stop heat stressing.
Perfect so im on week 5 of 9. Cheers. F4l

Fishing4life12 said:

Thanks staircase i holp since i mobed up my lights they will stop heat stressing.
Perfect so im on week 5 of 9. Cheers. F4l

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It’s not heat stress with LED. In fact plants under LED can tolerate a bit more heat.