Leaves curling up at edges

Discussion in 'Plant Problems' started by brainfood33, Nov 24, 2007.

  1. brainfood33

    brainfood33 Registered+


    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.

    Attached Files:

  2. Weedhound

    Weedhound Registered+

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

    Weedhound Registered+

    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?
    Last edited: Nov 24, 2007
  4. Weedhound

    Weedhound Registered+

  5. brainfood33

    brainfood33 Registered+

    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.
  6. Weedhound

    Weedhound Registered+

    Last edited: Nov 24, 2007
  7. brainfood33

    brainfood33 Registered+

    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.
  8. brainfood33

    brainfood33 Registered+

    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.
  9. Weedhound

    Weedhound Registered+

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

    Good luck.
  10. klondike_bar

    klondike_bar Banned

    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
  11. stinkyattic

    stinkyattic CultiModerVatorAtor

    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.
  12. klondike_bar

    klondike_bar Banned

    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.
  13. PharmaCan

    PharmaCan Registered+

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

    PC :smokin:
  14. Weedhound

    Weedhound Registered+

    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. :)
  15. brainfood33

    brainfood33 Registered+

    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.
  16. PharmaCan

    PharmaCan Registered+

    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:
  17. Weedhound

    Weedhound Registered+

    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?
    Last edited: Nov 25, 2007
  18. Weedhound

    Weedhound Registered+

    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. :)
    Last edited: Nov 25, 2007
  19. klondike_bar

    klondike_bar Banned

    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
  20. stinkyattic

    stinkyattic CultiModerVatorAtor

    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.

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