Thread: 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 growth is doing it and I'm getting worried.
I can't see a corresponding symptom in th faqs so I hope someone here can diagnose.

Many thanks.

You feed 2 week old plants three times? With one full strength? Can you say major league nute burn?

Wait ....hydro......what are you doing? They look massively burned and i'm sure they are.....but what the heck are you doing with the nutes? I think you'd better explain fully exactly how you are nuting these seedlings. Ad what is the ph of your water?

Start here:

A Troubleshooting form! Yay! You know you wanted one!

Remember it is in hydro so it is being watered constantly.

The plants aren't 2 weeks old they are 2 weeks in veg which is after 2-3 weeks developing roots under fluorescents.

I didn't think overdoing the nutes would have this effect and when it started whilst on 1/2 strength, I felt it was actually a nute defficiency after reading this site.

I think you have a HUGE amount of reading to do. Overnute and/or abnormal ph.....Good luck. \

allow me to ask however....your room temps? Somebody fooled me other day.....his room temps were 102.....if yours are way up there that could do it.....but I'm pretty sure its the nutes/ph.

Revised: The Complete Guide To Sick Plants,pH and Pest Troubles - PlanetGanja.com

You think they look burned?
I really don't think this is the case because I thought when you burn them, you literally get burning to the leaves and major discolouration and death.

These plants are green and generally healthy as they are growing and thickening at a staggering rate.

The PH is around 5.5 and I use a 3 part brand name (Advanced Hydroponics) and follow the directions on the label which per 100 litres of water is 60ml/30ml/30ml for vegative growth at full strength.

I HAVE done a huge amount of reading and I am just getting back into it again after about 10 succesful grows a few years ago so I am no newbie!

The temps are around 70f when lights are on and about 60f when off.
Humidity is between 40 and 50%.

You seem convinced its nute burn.
I would like to hear other opinions too please.

Oh....THEY WILL....give them just a little more time. They are on their way as we speak.

Good luck.

IM HERE!!!! lol

id agree on the nutes or ph. while its not a "burn", its definitely looking like theres an overdose of something, especially since it started at the base and ran up signalling something in the water.

check the ph and stop the nutes for a few days to see if it helps.

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

Originally Posted by klondike_bar

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.

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.

Originally Posted by 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.

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

PC

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.

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.

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

Originally Posted by 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

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?

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.

Originally Posted by brainfood33

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

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.

Interesting, thanks again folks.

A little update on the situation and a possible twist in the tale.

I've been measuring the PH only by using a cheap aquariam tester kit which is absolutely fine for readings between 6.0 and 7.6.
Now since its hydro I've been aiming for about 5.5.
My tapwater has a PH of around 8.0 so I needed to lower it significantly by adding the PH down.
The tester kit comes with a card with colour matches for each PH level with a pale yellow being 6.0. Since I was aiming for 5.5 I thought that I should be looking for a darker yellow but not quite orange colour based on full PH kits I looked at on the internet.

This is where I believe I have messed up!
I am an idiot!
Since reading this I've been investigating the situation further and suddenly realised that the PH indicator might not even change colour below pale yellow so I tested the babies water with a very acidic solution and there was no difference!!
Pale yellow is as yellow as it gets so what I thought was a PH of 5.5 could actually be as low as 4.5.
I need a real PH tester but I can't do that right now unfortunately.

So, could it be too acidic that its making the leaves curl up just cause its acid or could I be locking out some nutes because the PH is too low?
Would it cause leaf curl?

Stinky, I'm still not convinced its heat because some smaller plants have it too (they are 4 inches further away than that big one) and the air temp/circulation/ventilation/humidity are all fine.

Anyway, it was time for a water change so they have a fresh reservoir with full strength veging nutes with a PH of just less than pale yellow which should be roughly where I need it to be this time. At least it won't be pure acid anyway!

On the way I have fed my babies, I don't think it is a problem.
I grew lots of plants years ago with a 3 part and as soon as they went into full veg under the HID they were whacked upto half strength then full strength a few days later and I never had any problems!
This time I've gone easy on them by putting in the 1/4 strength step and spreading it out a bit longer.

Cheers again and I'll let you know how they get on but I feel that a stupid mistake like this must surely be the reason for the abnormality.

If you want to grow pot indoors, you need to know the pH of your water. PERIOD!!!



If you have to, go buy some litmus paper. If you have to, skip eating for a couple days and go buy some litmus paper.

PC

I know and I thought I knew what it was but I clearly had it wrong.

What is litmus paper and where can I get it?
I'll visit the growshop tomorrow and get something, maybe even a £40 meter

brainfood33 , try putting a fan(directly) blowing on affected plants. Seems transpiration is not happening fast enough for plants to keep up. Blow ye wind mate? full force,

Doesn't look like a Ph prob more like a transportation of moisture not being released into air? Just a educated guess?

Originally Posted by snakeskin

Doesn't look like a Ph prob more like a transportation of moisture not being released into air? Just a educated guess?

Snakeskin - A pH problem does not necessarily present itself as a "pH problem". Improper pH can cause a multitude of problems; and a multitude of problems can cause improper pH. What is vital for people to understand is that, regardless of your problem, pH is an integral part of the equation and you ain't fixin nuthin until you get your pH straight.

PC