flowering 6 weeks, yellowing wilting leaves, some with dried up burnt looking spots.

i have a couple plants going, smaller than the main plant which are all doing fine the main plant which is in the middle directly under the 400watt hps light about 2 ft or so above it. started showing issues about 2 weeks ago with some leaves on middle-ish shoots were doing a weird cupping like an upside down canoe then some had burn looking spots as well, i thought it could have been too much fertilizing so i watered it 2 weeks ago with plain water then a few days ago i flushed it and plan to do so again when it dries out, i thought the heat may of had something to do with it since some leaves had burnt looking spot on the sides of the leaves on some not all colas, so i put the light up higher to 1 1/2-2ft and have ac to keep it from 86 f down to 80f since they are 6 weeks figured should start having it cooler in there anyway... but the problem hasn't stopped, the bud growth has slowed, and now the top leaves on the main cola started to get a darkish yellow color to it turning more so by the next day and then the tip wilts and curls up and is soft, this has gotten worse on top the last 2 days, i've looked at a couple sites and threads pics and all and haven't had luck diagnosing the problem... cant be a heat problem, i wait till it is light when picking up to water it but not to the point where itd be drooping or anything.. maybe i just need to flush it with more water for a more thorough flush of the nutes.. help me out im posting pics of some of the leaf problems showing up and 1 or 2 are of the main cola

Whats the room temps ?

Did the problem start from the bottom up??or just the middle

Main branch fan leaves started yellowing and falling off first. Thought it just needed to do that for wasted energy. Then some leaves on middle colas did this upside down canoe cupping look.. The heat was up to about 88 and thats when some leaf edges looked dried and burnt so i put ac on and another fan and keeps it from 80-86. Now stays around 80. Put the light higher up as well.. then the main colas highest leaves started getting a dark yellow tint to them and then the tips shrivle and wilt then the whole leaf follows.. Pics show everything going on. Thanks

when did you get the temps under control? To me it looks like it could be too much heat/ underwatering. im scribed. Ready to see the answer from pros.

ive had the temps under control for about 1 1/2 - 2 weeks, they never really went over 86 but i could see how the light was too close, but hasnt been an issue for the last 2 weeks since its raised about 2 feet over the plant and the temp stays around 80 now. so i dont see how the heat could still be affecting it.. as for under watering i water the plant every 6-7 days when the soil is dried out and the pot is light lifting it up, but not to the point where anything would be sagging or drooping.... now i never flushed it with 3 gallons to every gal of soil, so it might not be getting an efficient flush, i put about 3 1/2 gallons of water and it runs off plenty, the run off did have a yellowish tint to it so figured theres some chemical buildup in there but a week after with the temps being contained at 80 the light being higher up and just plain water and the problem is not getting better but worse, each day for leaf at the top yellows at the tip then shrivels and wilts curling up and is soft.. cant figure it out, i dont think it can be a heat issue anymore, or anything with too much or too little watering id rule out, the only thing that stood out to me was too much chemical in the soil but seeing as how it hasnt helped any after a flush i dont know.. maybe not a thorough enough flush, which when the soil dries out ill be buying a bunch of distilled water and flushing it thoroughly.. 2 and a half weeks ago there was no problems was growing fine and looking pretty, just getting worse. need some more advise fast cause i cant figure it out. could it be something having to do with the roots? the pot its in isnt quite as big as i should have gotten but last year i grew 2 plants in the same size pots that were twice the size and still did perfectly fine.. help me out here

id think it was heat if the tips of the leaves were also getting crunchy and hard but they shrivel up after yellowing and curl up then the entire leaf blade follows, to the touch they are soft

soft to the touch at first anyway, the leaf blades that wilt and curl up coming out the main cola bud are soft at first but the next day are crispier at spots

It is normal for leaves to yellow and drop during later stages of flowering, the plant begins to use up all the nutrients in the leaves towards the end of its life cycle. Some blurry pics, but looks good to me.

its not just affected at the top main cola, that is the worst now, but other shoots are where symptoms showed first, the curl down eagle claw, upside down canoe look, and darking gray id say dry spots and shriveling of leaves, the after cooling with ac and raising light up and watering plain water thats when the main cola started showing whats going on now, pic 1 2 4 and 5 are the main cola and pic 3 is just on a lower shoot from the main just to show whats going on there which is happening on a good amount of the plant like that

not near the end of its life, is a little past 6 weeks since hairs showed and about 2 weeks of the problems showing, really the last week is where its been getting bad.. the growth has slowed and the buds are no where near the size they should be especially for the leaves to be doing that... i know the normal yellowing look and everything when its coming to the end of its life, this is not that happening at all.

Looks normal to me... Some people can keep the plants pretty green almost all the way through the life cycle. My plants start yellowing 2 - 3 weeks before finished and the product is always nice so...

Six weeks since hairs showed, so must have been on 12/12 for 7-8 weeks, I would consider that close to the end, unless you have a sativa dom strain.

Only other thing I can think of is Ph

yeah i mean 2 and a half weeks ago it was pretty and green now its showing all this and the buds not really growing much... could be sativa dom. not sure on that one.. i feel like i should see big fat buds or more bud anyway than what shes got.. i thought about the ph as well and its about 6.7 so thats fine i guess... why would the bud growth slow and leaves start wilting so bad 6 weeks in, and your dead on about it 7-8 weeks total 12/12, 6weeks since hairs showed took about a week and a half for the hairs to show... im going to take some more pics since people think its too blurred but i see the problem clearly in them.. thanks for your help keep it coming

heres some more pics of the problem going on

the 4th picture is of the same kind of strain but switched to 12/12 much earlier and is topped, in it you can see the yellowing leaves it will do when nearing the end of its life like mentioned earlier in the thread, so its much different whats going on then just that, the buds on it are much more developed and fat.. it actually seems indica dominant by how fast its going and the fat leaves.. the other 7 pics are of the big main plant so hope these are a little easier to diagnose my problem, bud growth is slowed to a stop it seems and the plants seeming weak as well, really really need help with this one this was the plant i was going to get the majority of my yield from, dont want it to die!

Yeah man... buds look a little scrawny. However, the yellowing leaves are normal in my experience during later flower. Idonno, looks pretty normal to me overall. Usually by the time I harvest, most of the fan leaves yellow up and fall off. Maybe I'm a shitty grower, but the buds are always primo.

yep scrawny is correct, thing is the growth was going fine and then just stopped then the problems started showing... so if your right and its supposed to do what its doing then me flushing the plant again instead of feeding it will only make problems worse since itd be depriving the plant of its food.. but i dont want to go throwing chemicals in it again if the problem started with too much nutes... what to do, what to do..

........usually if the problem starts from the top it's a toxicity and it the prob starts from the bottom usually a deficiency.......your leaves can curl downwards if not fed enough also....I had a similar problem with my lavender plants I currently have growing....my ppm meter was in need of calibration and was giving me inaccurate readings...I wasn't feeding enough.....the leaves on the lower shoots started curling and big fan leaves started eating at themselves kinda looking like fried leaves....I kept thinking it was nute burn so I flushed and kept lowing the ppms...well the prob got worst...finally I checked my ppm meter found out it was in need of calibration.....all my readings appeared higher than they were supposed to be........ so I was starving my plants......I gave them a higher dose and within a week things looked a lot better..

Yep, i'm still trying to find the fine line between overfeeding and underfeeding. I have always used Fox Farm Ocean Forest soil, which is pretty nutrient rich, and it seems to make feeding more complicated. As a result, I recently just went and got some organic peat and perlite, mixed it up so that I can try a non-nutritive soil and hopefully this will help me dial in my feeding schedule.