Sealed room problem with girls burnin up. WTF

So I sealed up my room and have had three troublesome runs in a row. Problem is mostly concentrated under the lights and gets less the further you get away. I'm starting week 6 of flowering. the problem started a few weeks ago with the plants yellowing. Now the lower fans are burning off and the flowers are starting to burn from the outer tip inwards. I don't see the typical tip burn from over fert. Heres some specs
sealed room
co2 at 900 (runnin it lower this time????)
85 degrees daytime temp
60% percent humidity
1000 watt lights
air cooled hoods 15 inches up
3 gallon pots
blackgold regular with perlite
water ph low 6
runoff ph around 7

I just bought a trimeter to look into the water and food levels better. I've considered the lights being too close. I vegged a little too much and the hoods are on the hooks. Also wondering if it could be a magnesium deff. just bought some cal-mag but haven't tried it yet. I just flushed 2 days ago with flora shield and then gave some root xlerator. Lookin for ideas on what to give them tomorrow. Any replies would be greatly appreciated. This problem is driving me nuts. the first pic is where they are headed. the second pic is one on the outer edge of the bed. then leaves.

Just a thought, have you tried separating your canopy from your light with a light penetrable cloth of some sort? I dont have any experience under a 1000w but i have seen a few others do that around here.

my outdoor this year had a few problems but i had 1 female that started doing what you have described and photographed. The buds actually burned through to the center and molded a day or so later. They didnt get an exuberant amount of light this year so i cant blame it on heat.

it doesnt seem like temp burn to me.

yellowing of lower canopy leaves and bud leaves is common towards maturation as the plant drains N from those leaves to feed its buds.

id say you have over/underfert , not enough N, too much of some Micro Nutes. as the plant drains N from the leaves, other nutrients get left behind and look like fert burn.

reduce your fert with micronutes by 1/5th, add N supplement.

your 1st pic looks like a sativa, looks almost exactly like damage ive seen on one of mine. seems to show up more towards the dry end of the watering cycle.
in mine i beleive it has something to do with soil ph changing as it dries out, causing the roots to uptake a higher PPM of nutes with the water.

best i can do hombre

Thanks for the replies. I'm trying to learn this new growing environment. The plants were uptaking a lot more than i am used to during the second to fourth week of flowering. Had to make improvements to get the humidity down below 70%. So during that heavy uptake I was provding nutrients at medium levels without any tip burn. But am I missing something, should I be supplementing somewhere? It's definatley an intense growing atmosphere, but I love the fact that I can control it better and the temp fluctuations are less. I'm thinking of giving the cal-mag to some, and maybe hitting some with a 20-20-20 fert. I hat to change things up but I gotta figure out how to quit stressin them out.

Anybody

Yeah dude that's MG def for sure. Same look mine have. Leaves look leathery at first then begin to brown and curl up. Takes a hell of a toll on your leaves but the buds should continue to grow just fine if you fix it. I flushed then added nutes with epsom salts. Have you begun a correction of some sort? Also, I stopped feeding veg nutes when I switched to flower. Looking back on it, I should have continued with veg nutes until about the second week of flower to store up on nitrogen. I'm thinking that may have contributed to the deficiency somehow. Just my $0.02.

i think you have a combination of things happening but your main concern should be nitrogen. try feeding them some vegitative ferts and there is a product called silica blast that i think would help as well. your bud does look good and should stay that way as long as you correct your def. also for future grows i highly recomend moonshine mix because its sooo simple and really works "just add water. good luck

Pretty damn sure it was a mag. def. I ended giving epson salts to a few, some nitrofen to a few, cal mag to a few, , , , ,. At the end they turned out good. From what I can gather the plants on the outer edges retained more moisture, which helped to buffer the overdose of phos. I was givin them. Just disconnected some of the ductwork to draw in the 30- 40 degree cold air and damn, they're goin a violet purp. I'll try and grab a pic