pale yellow leaves?

[Thaifighter]

The last couple days i have opened my room some of my plants have this pale yellow look in the middle of the leaves... They start to get darker as the day goes on.... what could this be?
The strains are super skunk and some bagseed which i was told was afghan kush... grown under 400w hps with roots organic soiless mix fed with plain water, my ph is around 6..
Chould it be the temp change when the lights shut off??
Day with the a/c 72-75 Night a/c off around 78-80
This morning




last night

 

[kmk420kali]

They look a li'l over watered...and maybe they are getting a bit big for those cups-- They might be at the end of their food supply in those, since you are giving plain water--
Just my first impression tho...Peace--

 

[midwestganja]

Almost looks like a iron or sulfur deficiency per the sick plant guide.. anyway you can take a closer pic of one of the ones yellowing on the top?

peace

 

[10k]

yea, they're ready for you to begin feeding

 

[cyberwax]

I would check ec and ph, then probably give em more nutes or i would completly overcomplicate it and do a rebuild of the growroom, buy an ro unit, change growing method and freak out. lol

 

[Pirate]

If it was mine I would probably repot (Looks like its time)......add a tad more N into the feeding.

What kind of plastic is that? Is it Panda Film or is that a grow tent?

Think about running the AC at night to reduce the heat. Sounds reversed to me. 72 or cooler at night and 80 day would be better. But I don't think that's what's causing your problem.
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[Thaifighter]

Thanks for the help guys.... i figured they were getting a little cramped in the cups, im gonna transplant them today...

Pirate- yea its a home made room with panda film and the reason i run the lights and a/c during the day is cause where i live the temps are 90+ outside and with the lights off during the day i cant get the room cooler than 85-90 so keep them off at night when its cooler.

 

[10k]

"If it was mine I would probably repot (Looks like its time)......add a tad more N into the feeding."

A little more N ? heh heh heh....Don't forget the P & K too.

He hasn't fed them anything but water at this point...cough...cough

 

[Thaifighter]

I repoted them today..... The reason i haven't feed them anything because my soil has alot in it... Ive been using this roots organic soil for about a year with no problems... i usually don't have to add nutes until the 2nd or 3rd week of flowering... but ive been thinking of adding something during the veg cycle anyway, just to give them a boost.

Ill stop by the hydro store pick up some nutes and ill update in a couple days..

Thanks guys