Possible heat stress?

So I don't ever post in this forum (plant problems). Usually I just ride it out and let them grow. After all, they are weeds right?

However, I just upgraded to a 400 watt MH/HPS and really want to do this grow the best I've ever done. I want them growing as perfect as possible the whole way.
The plants have been acting weird, but I've been LST'ing them and transplanted them, had to deal with a slight magnesium deficiency, so they are a little stressed which is to be expected.

My real concern is about the light, since I've never used such high power. I'm a little worried that they are extra stressed due to heat. Temps at top of canopy are ~86F and at bast of soil are ~75F. Top of canopy temps might even approach 88 or so...is this bad or does it not matter too much if the soil stays cooler? Note: I am NOT using the glass lens to shield heat from the bulb. I'm thinking about putting it in, but if I don't need it yet I'd rather just leave it out.

They've been growing ok, but very droopy. Its not overwatering, and even right after watering they perk up a little but are still droopy. I think I have 3 indica dominant and one sativa dominant. The sativa is the one I have a question about. The leaves started folding into a "V" shape and I'm not sure why. I've been watering with just water since I corrected the deficiency.

FFOF soil, pH'd water, pH of runoff is between 6-7, closer to 6. 400MH ~9-10 inches from tops of plants. Pretty good air circulation. 4 random seeds I got from a friend, so possible 4 different strains.

So does the leaf folding look abnormal at all or is it fine? My plan is to just keep going with what I'm doing and monitor, hoping it gets better.
Here are some pics:
First two are a day or two ago, third is most recent with the leaves folding up.

Your temps are too high. My hi temp for the day is 80 and i make sure to never let it go above that. 400w MH is powerful especially if you are using it to full power. Id say move the light 18-24" above the canopy. I have (2) 450 MH bulbs 2 ft. above my canopy and they are fine. Just my suggestion

My plant is about the same distance as yours and i am also experiencing heat stress lol.
My oscillating fan on full power isn't cutting it seeing as how it's the middle of summer.

Here's my leaves, you can see how only the serrated edges are sticking up like claws.

Anyway you can get outside air to cool the room down? I got an ac for summer and for winter I just use the air from outdoors. My room never goes over 78 degrees and never goes lower than 65 degrees.

tell me, you got a cool hood but you don't use it ?

my new cool hood with my 6" ventilation on it made my temps in my grow room drop about 5C
from +30C to 24-26C best investment I ever made, also allow me to keep it at 12-15" instead of +20"

View attachment 2451710


about heat stress, most visible sign is the leaf edges curling upwards, leaf`s that is "V shaped" like they are "praying to the sky" is a sign of healthy plant reaching for the light ..

yours don't look that bad at all, but Im sure the glass sheet on it with a nice ventilation will let you keep it close with out stressing them, either that or raise your light a bit ..

Thanks.
And Slipon, I think I'll put the glass on right now before the light turns back on. haha. Also, are you saying that reaching for the light like that, but not stretching, just means you have plenty of light?

Didn't really know if the lens was required, but I guess so. Wanted to wait until I had to do it. (Don't know why...I guess prove why I needed it or learn what heat stress looks like)

Not exactly a cool tube, but pretty good.

I think your good, just get that glass on and watch the temps, is there a ventilation pulling air out of the cool tube ? or how is that one working ?

and yes V shaped leafs that stand up like in pray is a healthy sigh tho to much can also mean that they get "to much" light
what your looking for or trying to avoid with high temps is curling edges, like a "cup"

aging I bet the galss will do the trick ..

Yes on top there is a slotted vent on top:



And then the box on top in my picture is an additional cooling attachment that has a fan inside it, pulling air through the vent and blowing it up through the ducting. There is a big vent on the front in front of the bulb that the air is drawn in through when the glass is in. There's also 2 on the top sides where it does the same.

They are praying to allah, cool the temps down. The ph is out also so get a digital ph meter and water and feed at 6.5.

Ph of runoff is between 6 and 7. Have a wal mart aquarium ph test kit where you put the drops in the vial.