Help! leaves curling up shriveling and browing!

Hey guys,
I need some help. I have 4 great white shark seeds growing under a 400 Watt HPS bulb with two blizzard fans going. All of the plants look fantastic besides one. It is about 2 feet from the light but some of the higher leaves are yellowing and curling up around the edges. They are crispy and will crumble if u touch them. My first guess is heat stress but the temp in the room is about 80 degrees F and i have two fans on high pointed at them. Am i not watering enough? I cant put pics up right now my camera is broken! please help asap!

sounds like a heat problem. 80 is pretty warm for these girls, you need to get it to 75 or below. Also might want to check the run off PH.

good advice or if the ph is ok and 80 isnt extreamly hot it may be an overwatering problem

This may help https://www.rollitup.org/view.php?pg=faq&cmd=article&id=171

overwatering/over ventilation/limited freshair/ph 6.5 for soil 5.6 for hydro

i use a spray bottle to water and i water the soil until the top is wet. but if i move a little off the top of the soil its dry thats why i thought i was underwatering. also the water evaporates quickly because its alot of light to a small amount of plants. what do u guys think
?

it depends how small ur plants are if theyre small they dont need soil AND leaf waterings
i stick to my answer above
u also need more info
soil how u water it (is there stem rot) like dat

no theres no stem rot. the plant is growing very healthy. all the leaves are healthy besides 4 of the leaves edges. its about a foot tall and very bushy. i usually water the leaves lightly and then pour 100 ml of water around the base of the stem. i water them once a day. is that too much or too little?

Water when you can't find any damp soil with a fingertip, or maybe spend 10 bux and get a moisture meter. Your watering method is rookie. Water thoroughly when you do water, until it starts running out of the drain holes. Occasionally take a stick (bamboo skewer?) and aerate your soil (like tenderizing a steak) to encourage even moisture and complete watering.
Then drain well. Any more than twice a week would indicate (to me) that there are other things needing adjustment, like heat, wind velocity, etc.

I don't think most experienced growers run their surface fans on HI? Wind-burn is possible and a constant strong breeze tends to dry out what it's blowing on. I thought the object was to run the fan between the lights and the top of the growth, to reduce ambient heat.

thank you very much that helps alot

[he majority of time its moisture on the leaves that causes them to curl up and even spot or discolor where the water droplet was/is . Here is what happens; you spray your plants down lightly or heavily... the leaves soak up water almost allthe way thru... your lights heat that water and the leaves curl...evenly if watered heavily or complete coverage.....with spots if just misted or sprayed.

If you must water or clean your leaves, use soapy water to battle spidermites or whatever, NEVER DO IT WITH THE LIGHTS ON!

wet leaves and any radiated heat at all is a bad thing and i start all mine under CFL, so i have learned this important lesson twice, once with HPS as well.