Leaves curling up at edges

[stinkyattic]

IM HERE!!!! lol...
also bring the lights within about 8inches, they look old enough to handle that and itll give em more energy

Great. NO. Do NOT drop the light!!!

Those plants look VERY healthy but they are heat-stressed from the light being TOO CLOSE ALREADY.

Raise the light.

What's your %RH? Up-curled edges are a sign of acute heat stress often combined with an arid environment.

stinkyattic Reviewed by stinkyattic on 11-25-2007. Leaves curling up at edges Hi, I've been growing this Jack Herer from seed and they're just coming up to 2 weeks in veg. Its a hydro setup and they are under a 400W metal halide which is 11 inch from the tallest plant. They have only just made it to full strength nutes after spending the first week getting 1/4 then 1/2 strength before hitting full strength a few days ago. The problem though, is that most of the plants are showing this leaf curl in varying degrees. It starrted on the lower leaves but now new Rating: 5

[klondike_bar]

too close? usually those lights are set about 6 inches. those plants look onl and green enough to handle the higher temps. (thats why i said 8 as compromise however)

i say its some kind of nutrient or ph problem.

[PharmaCan]

too close? usually those lights are set about 6 inches. those plants look onl and green enough to handle the higher temps. (thats why i said 8 as compromise however)

i say its some kind of nutrient or ph problem.

So now you're going to tell Stinky she's wrong. :wtf:

PC :smokin:

[Weedhound]

I could buy the lighting too close.....although 11 inches doesn't SOUND too close....the plants WERE under flouros and then he went to 250w....that's why I gave him the link to Plant Problems.....so he could figure it out on his own since he said room temps were fine. The only info I was givien was the reference to raising his ppms three times in one week on new plants and no discussion of ph. Without all that info its MUCH wiser to give him the plant illness guide to study.....or have Stinky take a look.....which she did.

[brainfood33]

Thanks for your responses everyone, its my first time posting here.

But I'm getting some mixed opinions which is to be expected with such a variable, wild and wonderful plant!

So, Stinky, you don't think it looks like overdoing it of the nutes then?
I was considering a flush with plain water for a few days but they are so green and lush that it didn't feel right to do it.
If its not nute burn then could it be nute defficiency?
My RH% is between 40 and 50 and the temps are between (60 and 70 night/day).
The PH is always between 5 and 5.5 but is it possible this is too acidic?

Its only a 400W metal halide and it didn't feel too hot on the back of my hand so I thought they were safe. And it is also present on plants that aren't as tall as that one and are not directly under the light like he/she is which was another thing that pointed away from that for me.

But Klondike, I have had these lights in the past and 6 inches is definately far too close as that would burn my hand after a few mins!

Thanks again everyone and if you have any more thoughts they will be most welcome.

[PharmaCan]

Your pH is way acidic. It should be around 5.7.

Are you having fluctuations from 5.0-5.5? (Your pH goes down and you adjust it up, then it goes down again - that type of thing.) If so, that's not really ideal for hydo. Are you using r/o water or tap?

PC :smokin:

[Weedhound]

Your pH is way acidic. It should be around 5.7.

Are you having fluctuations from 5.0-5.5? (Your pH goes down and you adjust it up, then it goes down again - that type of thing.) If so, that's not really ideal for hydo. Are you using r/o water or tap?

PC :smokin:

I agree with this butI still want to know ppms here.....I've never in my life jumped a plants ppms three times in one week.....that would terrify me! (And he DOUBLED THE DOSAGE each time!!)

The problem started at the bottom......which made me think less about lighting. I WOULD take ph up to 5.7-5.8 as PC says but I REALLY want to know the nute numbers.

How closely to the time you changed your light did the issue begin with the curling and having you been checking ppm and ph regularly? If so.....what is the trend?

[Weedhound]

One other thought for nutes/ph vs lighting......he said the plants were growing great guns....VERY common with nute burn since the line from one to the other is not too far. One minute they ARE growing great....then they are burned.

With lighting I don't think they would be that green and growing that well.....the heat of the light would have caused bleaching etc....

These are my thoughts. Good Luck.....I really do mean that.

[klondike_bar]

But Klondike, I have had these lights in the past and 6 inches is definately far too close as that would burn my hand after a few mins!

in that case, it may be a heat issue. i have not grown with hid lighting before, but from my readings in paper and online, 6inch appeared to be the satanderd hieght of those bulbs

[stinkyattic]

My finger is on the ban button. After all this, "it may be a heat issue"... HAHAHAHAHAHA I'm dyin' over here. I don't know whether to laugh or beat my head against the table. "I have not grown with HID lighting before"... So what the %@#& do you know about its practical application?

Actually Pharma and Hound are the ones to listen to about the ppms and pH in hydro. That bump-up is fast and harsh... go easy when making changes, especially on your first go-round, and watch your plants to see how they react. Those plants ARE beautifully lush. Keep an eye on the very tips of the leaves and if you see any scorching, back off the ppms.

Remember that lush new growth is SOFT and tender and will react differently to heat. Your plants are being fed aggressively and the fresh leaves are a little vulnerable. A silica supplement wouldn't be a bad idea at this point, but make sure your total ppms are not too high.

I don't see ANY signs of a nute problem yet but you may be setting yourself up for one. Take care of the heat first. An air-cooled reflector is your best friend.... seriously... best hundred bucks I have EVER EVER EVER spent in my grow room!

That curl is a heat issue, straight up.