Leaves curling up and going shiny

[daveros34]

Hi all.
Any help or tips on this matter would be very welcome.
I have some Bubble Kush seedlings, all are displaying the same symptoms.....Fan leaves curling up and going shiny.
I have a 2.2 x 1.2 x 2m grow space, 2 x 600 watt hid lights....1 x intake 8" fan 1 x 8" extraction fan...3 12" circular fans to move air about.
My temps at canopy level are 75-76 C but RH is at 35 at the moment.
I have struggled with them for a couple of weeks now. They are growing slowly but the new growth lasts a day or 2 then curls.
Im using a 75% coco 25% perlite pot mix i made. My PH of nutrients when i feed is 5.8 - 6.0.
I am using 1.5 ml canna A + B 1 ml Rhizotonic and 1 ml canazym to every litre of water.
I water usually every 3-4 days. Lights are on 18 - 6 .
I have never had this trouble on my last few grows (i have never done 1 this time of year before....nothing to do with low RH maybe? )
I have attached a few pics to show whats going on with the plants.

Cheers Guys
D

 

[VladimirPutin]

Water your plants with plain 6.5 ph water and check the run off. You may already have created a nutrient imbalance so check the PPM of your runoff water to have a better idea. If you don't have a meter for PPM, just flush them with 3x pot volume of water, do it in the morning never late in the day, they could drown. Damaged leaves will not recover. Don't pluck any leaves until new growth is healthy and vigorous.

Welcome to 420Mag

V

 

[daveros34]

im due to water tomorrow so will try this out...thanks dude

 

[Papageno]

I assume 75C is a typo (because they would be dead very quickly at that temp) and you meant F.

But they are showing signs of heat stress or Light stress. How far away is the light source you described?

40% RH is the absolute bottom...below that and you are stunting growth. Most try to keep it closer to 60%. Hang some wet towels in there to get the humidity up.

Ideally you want to be around 24 C and don't go over about 27 C.

 

[daveros34]

hi and yes 75 f lol ty. my lights were about 2.5 ft above plants and yes RH is low so i will try the hanging towels up too. also move the lights up a little more too. thanks.

 

[thebeast27]

I reckon 2 600 is just to much at that young age.switch a light off mate and use 1.bet u see things start to improvebest of luck

 

[KidGrow420]

Ya, I concur. That leaf damage is heat/RH related 100%. Temps should be around 26-28 at this stage of the game for you, and the RH 65% - 80% (max) To me, that looks like there wasn't a efficient enough airflow over the lights. It's ok to have this much light, but you must have some sort of 'cooling system' over the lights,(Fan blowing directly on it/them or a decked out exhaust cooling system) because they can give off some serious heat. You can even try raising the light a bit as well. Just keep in mind there is a "too close" or a "overdose of light" point, especially with younger plants. They do not need to be so close when the plants are so young. You can just raise them a bit... But as for co$t efficiency on your pocket. It's not worth it when they're this young. 1 600 watt directly over them will be more then ample enough light. Here is a chart you should follow;

There is no chart for 600w. But you can easily average it out with common sense Hope this helps ya a bit meng. Keep the fight up those girls will survive and thrive!

 

[BooMtoLate]

This is a super old thread, but my plants look the same as yours. Did you figure out the problem?