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Thread: Leaf curling

  1. #1

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    Lightbulb Leaf curling

    Hi everyone,

    Bringing another part of my grow diary here as nobody seems to be viewing the diary lol.

    I swapped out my 250w HPS for my 600w HPS 2 days ago and all was going well, the plkants were growing well and noticeably quicker. I was getting temps of around 25°C at 15" so I got a bit greedy and lowered the lighting to 10-11" which was giving me temps of around 28°C.

    Anyway since lowering the leaves have curled at the edges overnight (no discolouration though) I am guessing this is a heat issue? Surely 28°C isn't too much? I can hold my hand under there for 5 minutes no problem. Anyway if you copuld take a look at the pictures and give me your opinion that would be great.

    This morning I raised the light to 13" to help alleviate the issue.

    Click image for larger version. 

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  3. #2

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    That looks like heat stress. You need to lift that 600 up a bit more and make sure you have a fan blowing over them

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    Quote Originally Posted by Officer Crabtree View Post
    That looks like heat stress. You need to lift that 600 up a bit more and make sure you have a fan blowing over them
    I thought as much OC. I have raised the 600w by 3 " from 10" to 13" so that should help, I have a 7" oscillating fan on them too.
    How long does it usually take the leaves to rectify if the alterations are OK?

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    Quote Originally Posted by AutoManCan View Post
    I thought as much OC. I have raised the 600w by 3 " from 10" to 13" so that should help, I have a 7" oscillating fan on them too.
    How long does it usually take the leaves to rectify if the alterations are OK?
    I would lift it a bit more than that. The leaves will most likely stay like that now but it's nothing to worry about mate. Keep a check on your RH as well as that 600 will dry the air out. Aim for around 50% if you can and that will be sweet as

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    Quote Originally Posted by Officer Crabtree View Post
    I would lift it a bit more than that. The leaves will most likely stay like that now but it's nothing to worry about mate. Keep a check on your RH as well as that 600 will dry the air out. Aim for around 50% if you can and that will be sweet as
    What would you reccomend? 15" or 18"?
    I will plug my humidifier in tonight to keep it around 60% until flowering when I will drop it to around 40-45% and 35% late flower.

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    Do you have a fan for circulating the air in the grow room?
    "Accuse the other side of that which you are guilty."
    (Joseph Goebbels)

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    Cover 'em with a couple of 2L plastic bottles (cut in half), refresh the air every 12 hours, that'll get some RH in and around 'em.
    In terms of a sweet spot , I aim for 70% +/- during veg, 40% +/- in flower.

    ATB

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    Quote Originally Posted by M_C View Post
    Do you have a fan for circulating the air in the grow room?
    Yes, I have a 7" oscillating fan.

    Quote Originally Posted by rockhopper View Post
    Cover 'em with a couple of 2L plastic bottles (cut in half), refresh the air every 12 hours, that'll get some RH in and around 'em.
    In terms of a sweet spot , I aim for 70% +/- during veg, 40% +/- in flower.

    ATB
    Yes I did that for the first week so may do it again now.

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    Ah! I see the problem!

    Any chance of a pic where we can see both the plant & the top of the pot?

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    Got it



    Having the soil level so low creates a different environment in the pots as it creates a heat trap in the pots that the fan can not effectively shift

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    Quote Originally Posted by M_C View Post
    Got it



    Having the soil level so low creates a different environment in the pots as it creates a heat trap in the pots that the fan can not effectively shift
    Damn,

    I suppose there is nothing I can do now other than add a small clip on fan pointing down to disturb this trapped air?

  20. #12

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    Lessons learned for the future mate, always fill the pots up

    You'll most likely be fine with the grow, just accept a bit of heat stress until the plants grow a little larger

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    I'm also using a 600 and struggle with the temps at this time of year mate I'm about 28-30 atm I get similar leaf curl to what you have. Not much else I can do in terms of affordable solutions.

    The only thing I do now is use cool mist humidifiers which can lower the temps a couple of C. I also lower my extraction closer to my light to suck the air out as quickly as possible.

    Temps are a pain in the summer sometimes we just have to take a bit of heat stress. As long as it doesn't get worse then it's not a major issue. Just grow more in the winter mate

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    Quote Originally Posted by ReeferDankness View Post
    Just grow more in the winter mate
    Now that my friend, is a dank idea

  25. #15

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    Okay so I raised my lights to 16" due to the heat stress and curling (they were at 10")
    The temps have now dropped to an average of 25-26 degrees Celsius.

    I was having issues with my humidity again sticking at 40% so I have put my humidifier in on a high setting to ramp it up. I want between 60% and 70% until flowering.

    Here is the humidifier in action


    Here is a photo of my plants with the lights off and the flash from my phone as requested by Joker The Smoker.
    I set my white balance to Auto to try and capture the plants true colour, with daylight white balance they looked lime colour.



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