cupping leaves????

I've had upper leaves cup upwards or "canoe" on me before from heat stress. Solved that problem with just getting the canopy temp down or moving the light up a bit.

But this time, I'm getting lower fan leaves doing the same thing even though the canopy temp has been a steady 73-76ish. The weird thing is the upper fan leaves are perfectly fine. I wonder what's going on here??

Anybody??

either soil is running hot (not broken down / cooked composted) or the room is too hot. The leaves taco and edges flare to cool itself off. Now if the tips start curling upwards then that's under watering.

Welll...im in soilless so...unlikely that its hot...unless over nuting possibly?

And to keep the canopy temp in said range the rest of the room is much cooler ...round 70/71....

This is where my confusion is...

Im using dutch master gold and hitting them at about 1400 ppms....would that heat up soilless?

Anybody???

what is the humidity and heat like up at the canopy?

When the RH in the room is very low this tends to happen. The few times this happened to me the RH was in the 20s and each time I raised it the leaves flattened out within a few days.

Well...the humidity has been really low. During lights off it raises up to 40%ish, but when the lights come on its around 32-35%ish. It fluctuates with the a/c going on and off. Plus... the ca4bon filter is probably sucking some out. The 32-35% is with a humidifier going....high as i can get it...

I dont know what else to do to get the humidity up. Its just the cold outside air around these parts just has no humidity...on going fight...

What kind of humidifier are you using?

rezball said:

What kind of humidifier are you using?

Click to expand...

This one
http://www.homedepot.ca/product/honeywell-cool-moisture-humidifier/958689

I tried a few. An ultrasonic one that was suppossed to be good for 700 sq ft and a tower....

The one in thebpic has worked the best so far...

Most of them are ineffective and a waist of money. If you want one that actually works this is the one you want. I've tried multiple humidifiers and this guy right here is the only one that could raise the RH up to appropriate levels with ease. The hygrometer on it is very accurate and automatically shuts off when the set rh is reached. The only downside is if you put it on high its pretty loud because this sucker moves a lot of air but on low its pretty quiet. I keep my rh at 50 most of the times but this sucker could pump it up in the 70s if I wanted it to. Without this thing my RH sits in the upper 20s this time of year. Same price as the one you got but 100 times better and effective. Look into one

http://www.homedepot.com/p/Essick-Air-Products-2-26-gal-Evaporative-Humidifier-for-1700-sq-ft-MA0800/203019394

I will tell you though the cause of the tacoing leaves is from low RH a lot of the times. I'm absolutely certain it was in my cases. I wish I had some before and after pics I could show you.

The reason the lower leaves are tacoing and not the uppers is because the upper leaves are newer growth and have yet to dry out. They eventually will if you don't take care of the issue.

Thanks for the tip o the humixifier. I guess mine is simply under powered even though its rated for a room twice the size.

And you're right...i see a few uppers here and there that are starting to curl :/

Ill get after it...

lights to close ?

Well...just by chance i think i figured out the problem....

I picked up the latest issue of Skunk mag and actually found some useful info amongst all the bud porn. Turns out that cupping leaves is not only a sign of heat stress or low humidity, but also of low ph. And i have been phing mine around 6.3 (in soilless) because i read that more bloom nutes get taken up at that level.

Just in case anyone else is having the same prob....

Makes sense to me I'm week 7 into flower and my leaves are tacoing too I just added some garden lime tho hopefully it'll raise the pH, that on my Maui Waui but my other strain ak-49 thr leafs aren't doing that. I'm in soil tho using espoma mix soil admenments.

But now that I think if it, It might be cuz it's under the hps and my ak-49 is under the LED panel and it's not tacoing its leaves.