Leaves are curling up. What to do?! Help!

I've been vegging GDP's in 6"x 6" cubes for about 10 days. It's steadily growing quiet big but my leaves are curling up. What is the problem?! I'm freakin' out! My room temperature ranges from high 70's to low 90's degree. The humidity is at 30's-40's when the light is on and in the 50's with the lights off. I have my 1000k watt HPS 24"+ above the tallest baby. If the room gets too hot say over 90 degree, I would adjust the dimmer. Light cycle is 20/4. Ph is around 5.5-6.0. I just did a flood and now they look "DROOPY". Second time feeding it. Don't know why I did it because I fed it two days ago and the cubes were somewhat heavy. I'm not sure what the ppm is since I don't have a reader. Please help. I appreciate your input.

I've personally not experienced curling of leaves to that affect, however I do notice cupping of serrated leaves when temps exceed 85-86 for long periods in my small closet type grow with 550w. Perhaps this could be a sign of heat stress, although I would wait for some experienced growers who have been through the same to weigh in.

In the mean time you can view heat stress symptoms and see if they perhaps match what your seeing with the canoeing of leaves. Perhaps there is possibly more causes to it then just heat stress, although 90 for extended period in a closed area could probably canoe leaves substantially.

I don't think I could hold 90 in my small room for long without having similar signs of stress, only 1-2 hours of 86-87 when a/c shut off showed enough stress for me to change light schedule to align with day time when a/c is on.

Looks like heat stressors, perhaps not enough room to transpire adequately coupled with that. Do you have a circulatory fan on, ensuring there isnt too much co2 enrichment?

Leaves curling upward like such is an environmental issue (high heat, humidity etc). Leaves curling down is a nutrient issue (soils too "hot", too much nutes in hydro etc).

Get that heat under control ! 90F= dying, limited, plants. You know your problem, it's the heat, as you said... now just fix it, before it's too late... Good Luck! NEVER let it get above 82-83 f... why 'just' 82 f? Because you will see the 82, and you have hot spots, where you do not see temp, [top of plants?] Fix the heat or your plants will suffer a slow death, and there will be nothing you can do!

The leaves look to be canoeing too me and the leaf tips are not upturned. I think they are more praying for Magnesium rather than heat stressed.

it was a heat issue when this happened to me, though i had 90 degree temps 50-60%rh through most of veg and never had much of a problem. When the leaves started canoeing i just raised the lights a little and that went away.

Your plant if heat stressed, will show symptoms of lock out... If it gets worse, sorry.... hopefully it gets better... if not, and it starts to get worse, You'll think PH problems, because roots will quickly dry up and turn brown and die... I had an AC quit on me recently, and only the plants in need of being watered, had heat issues. Limp leaves, wet-ish looking is the next step, to Heat stressed plants...

I had the exact same thing; "canoeing" (where they kind of fold in half) can be like magnesium deficiency (I think), but when the leaves start turning really shiny and really curling up around the jagged edges like that, its from heat.

If you can get the temps under control the plants will survive but those leaves that are really curled at the edges Will stay damaged until they fall off.

your leaves are curling up towards the inside. like everyone else said, its a sign of too much heat

Good Luck man...

HeadieNugz said:

Looks like heat stressors, perhaps not enough room to transpire adequately coupled with that. Do you have a circulatory fan on, ensuring there isnt too much co2 enrichment?

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I have a honeywell oscillating stand up fan and dual window fan. Is that adequate enough?

Sand4x105 said:

Get that heat under control ! 90F= dying, limited, plants. You know your problem, it's the heat, as you said... now just fix it, before it's too late... Good Luck! NEVER let it get above 82-83 f... why 'just' 82 f? Because you will see the 82, and you have hot spots, where you do not see temp, [top of plants?] Fix the heat or your plants will suffer a slow death, and there will be nothing you can do!

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Temps can reach up to 90-92 but average is mid to high 80's. I definitely don't want my babies to go away.

My current temp is 84 and h. is 45. My in-line is on full blast until lights off. The light is dimmed to 75%. Do I need to up the h if so how?

Alexander Supertramp said:

The leaves look to be canoeing too me and the leaf tips are not upturned. I think they are more praying for Magnesium rather than heat stressed.

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Do I need to get some MG? I mean I followed what the GH's instructions are.

rhymeshark said:

Do I need to get some MG? I mean I followed what the GH's instructions are.

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Wouldnt hurt to foliar feed them some Epsoms Salts until you sort things out. 1/2 tsp per quart of water should do.
It could be some heat stress also though, 24 inches with a 1000 is kinda close. I would back it off to 36 inches or so....

Alexander Supertramp said:

Wouldnt hurt to foliar feed them some Epsoms Salts until you sort things out. 1/2 tsp per quart of water should do.
It could be some heat stress also though, 24 inches with a 1000 is kinda close. I would back it off to 36 inches or so....

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What's foliar feed? 1/2 tsp/quart is that all? My lights are dimmed to 75%-50% accordingly. Where do I find epsoms salts? Walmart, local hydro?

Thanks you guys for your time and input. I'm a first timer so please bare with me.

Its a swing and a miss, again. Nice try kiddies.....

Just sprayed some salt and keeping my temp under 85. Is there any technique to feed? Do I jus spray the area that is needed or the whole baby?