New Grower - Is this Heat Stress?

Hey All...
I'm a new grower and about 20 days in the veg state (18/6 H of light). Already encountering my first problems... My indoor grow area is about 4sq.ft (1,5 sq. m). The temp flactuates from 71F to 77F (22C - 25C). Humidity is 58% - 75%. The water pH level is 6.5 and the soil pH about the same. I am using BioBizz nutrients.
As you can see from the pics attached some of the leaves firstly demostrated some "indentations" on the top parts. Like small inward dents. Then some of the edges curved upwards and now some leaves appear brittle and dried. They feel like paper... I researched the symptoms and thought that it is heat stress, so I moved away my 400W MH lamp (from 1,7ft/52cm from top leaves) to 2,2ft/70cm resulting in slower growth. I don't know what else to do... Do you have any ideas? Is it indeed heat stress? Or is it nutrient burn?
Any help from someone more experienced would be appreciated.Thanks in advance!

I'm unaware of what that is but it's not heat stress

i think might b caused when a fan is pointed straight at the plant??but im just goin off of wut i have seen with my grows

have u tried sprayin them with just water when ur lights r out?

its from having a fan blowing them too much its stress basically.. it does that to me when i turn my fans on hi. nothing to worry about i dont think.

no its not it happens to me as well cuz i have three fans in a closet grow lol

hyltonsown said:

have u tried sprayin them with just water when ur lights r out?

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Yeap.. I'm doing that since they started showing symptoms

I'll try lowering the fan speed and raise it higher... Let's see what happens...

Agree - seems more like wind burn than heat stress - temps are within acceptable range (can even drop a few degrees more during dark time) - 400W MH in a 4 sq ft room is plenty of light and 2' is ~ height needed. Ph's look good. I had a similar problem with 1 plant in my set up - through process of elimination I discovered that the venting of the digital ballast created a cool wind stream on the lower portion of the afflicted plant - I have moved the plant (will move the ballast when grow is done) - It seems to be improving as new growth is vigous and healthy however damaged leaves are slow to recover.

your plants are too wet

i say again - your plants - they are drowning

let your soil dry ou a bit more before you water

pick your plant up wet
water whne it weighs 1/3 that

Thanks Bud. All help is appreciated!

Got that mate! Thanks for the advise!! I've stopped watering the the last couple of days... Just moistening the leaves when lights are out!

are you spraying them with anything other then water?

Tiffay2180 said:

are you spraying them with anything other then water?

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No Tiffay... All other nutrients are either in the soil mix or added to their water... Why? Should I be spraying them with something else?

MrNash said:

No Tiffay... All other nutrients are either in the soil mix or added to their water... Why? Should I be spraying them with something else?

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haha no sometimes sprays can warp leaves.

Tiffay2180 said:

haha no sometimes sprays can warp leaves.

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I'm growing Bio so I am avoiding anything in sparayable form just in case... no harming to the ozone layer was caused during this grow and the carbon footprint is kept to a minimum and shit.. LOL
Thanks for the input!!!

Just an update: I lowered the fan speed and raised it's height so it's not hittinh the plants. I let them dry out for 4 days before watering them and adding any more nuts. I also installed air circulation with two air inputs and filtered air output. They immediately showed signs of improvement and healthy new grow... I also tried out Fimming the top shoots 4 days ago which worked fine for my girls (so far)... Here are some pics...
Thank you all for the input and the help... It has worked out fine till now!! I'll keep you posted!!!!