First time with HPS... What the heck is happening?

Il Cuoco

Il Cuoco

Member
Hi bros...i wish I was a lil less high while writing this thread but...life is life...

anyhow, this morning i woke up and saw somthing that hurt my eyes: my lil children have slightly curled edges...i moved the lamp 10cm higher (about 4''), switching the temp from 33° to 27° (approx 91 to 80 farenheit) ...

Given that 91 degrees doesn't seem to be too mutch (at least this is what I think, i've always grown outdoor) i don't really believe it was heat stress.

I am doing a 20/4 light cycle with easyriders, following my seller's advice...so i don't think it is a light stress problem.

Water is just ok...earth always umid under 1/2 inch or a few more.

Can anybody help me find out what's causing the leaves to curl like this?

foto:



...and here's the full resolution link :

http://img51.imageshack.us/img51/7135/21122010023.jpg
 
palerider

palerider

Active Member
90deg is too hot man, I wouldn't go higher than 80 indoors unless your using co2. I personally keep my room at 75 daytime 68 night
 
cowboylogic

cowboylogic

Well-Known Member
For a plant that size 400 watt 18 inches min. 600 - 28 min and 1000 - 36 min.....and 90 is way too hot. 80-82 max
 
SmeLLyTreeZ

SmeLLyTreeZ

Well-Known Member
palerider said:
90deg is too hot man, I wouldn't go higher than 80 indoors unless your using co2. I personally keep my room at 75 daytime 68 night
Click to expand...
90 is to hot but you can still make do. Of course 72-76 is the best temp for growing but you can grow in high 80's low 90's without extra co2...
 
Lil Czr

Lil Czr

Well-Known Member
Yeah man, that's too hot for little fellows like that.

Most bigger plants don't love it that hot either.

85 F is about as hot as you want to go in any normal situation.

You want lost of air circulating regardless.
 
Il Cuoco

Il Cuoco

Member
Thanks for everyone...I just thought that, as here outdoors reaches 90 and sometimes up to 100, it was ok...

I just didn't think that outdoors there's fresh, constant circulating air.

I'll have to keep the fan up but i'm going to spend a fortune on electricity... only the hps eats 60 bucks a month...

By the way...it's worth it!
 
jondamon

jondamon

Well-Known Member
The problem you have been experiencing is caused by Humidity being too low.

This causes a major difference in VPD's (vapour pressure defecits) which means your plants cant transpire properly which causes the leaf roll.

Usually there are 2 things that can cause this issue.
1. Your lights are too close causing the leaf surface temperature to be higher than the air temperature causing a very low RH and a very high VPD which makes the leaves roll.
2. Your oscilating fans are blowing too directly at your plants causing a lower RH on the leaf surface again causing the leaf roll.


Solution
Raise lights and ventilate or go air cooled.

Or redirect your oscilating fan.

AS plants get larger they transpire more and release water vapour into the air adding to the RH. Alot of people that dont have full control over their environment experience this in the first few days/weeks of a plants life you can either respond by sorting it out or wait it out and see if it gets better as the plant gets bigger.

If its caused by the heat which in this case it probably is then you need to correct the heat issue.


J
 
Il Cuoco

Il Cuoco

Member
jondamon said:
The problem you have been experiencing is caused by Humidity being too low.

This causes a major difference in VPD's (vapour pressure defecits) which means your plants cant transpire properly which causes the leaf roll.

Usually there are 2 things that can cause this issue.
1. Your lights are too close causing the leaf surface temperature to be higher than the air temperature causing a very low RH and a very high VPD which makes the leaves roll.
2. Your oscilating fans are blowing too directly at your plants causing a lower RH on the leaf surface again causing the leaf roll.


Solution
Raise lights and ventilate or go air cooled.

Or redirect your oscilating fan.

AS plants get larger they transpire more and release water vapour into the air adding to the RH. Alot of people that dont have full control over their environment experience this in the first few days/weeks of a plants life you can either respond by sorting it out or wait it out and see if it gets better as the plant gets bigger.

If its caused by the heat which in this case it probably is then you need to correct the heat issue.


J
Click to expand...
This definitely make sense...thank you very much i'll be following these rules and see what happens.

Anyhow now, two days later, leaves are still curled, but newer ones aren't, so I think i have just solved my problem.

It is just curiosity as for this time it wasn't too late to harm the plant's life, but if i'll have to leave the plants alone for a certain time (let's say three or four days), and given that, once came home , i would find heat-stressed plants, will those leaves ever heal back or they will rest curled forever?
 
Highlanders cave

Highlanders cave

Well-Known Member
No those leaves wont heal. It doesnt matter those first sets of leaves dont even count as your first node. I dont know why your using that light for seedlings. a couple of cfls in the blue would work a lot better
 
Barnsy73

Barnsy73

Active Member
It is just curiosity as for this time it wasn't too late to harm the plant's life, but if i'll have to leave the plants alone for a certain time (let's say three or four days), and given that, once came home , i would find heat-stressed plants, will those leaves ever heal back or they will rest curled forever?[/QUOTE]

No usually it kills the leave's and they fall off I would really try to keep up the humidity level thats what it looks like to me also that will help with the heat
 
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