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Thread: Pics of sick plants - please help diagnose

  1. #1
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    Question Pics of sick plants - please help diagnose

    Newbie 1st grow desperately need help diagnosing why leaves are turning yellow/brown

    Some of my fastest growing plants are yellowing and dropping leaves - other planets seem just fine

    Problem seems to be getting worse after trying to let them dry out more and selectively fertilizing

    I've looked over various disease charts, troubleshooting guides, leaf pictures and grow posts

    BUT - I just can't seem to decide what it could be - so many possibilities seem to match up - no experience yet

    My theory was overwatering or lack of N - but trying to adjust this seems to have accelerated the problems

    Please help - I've included pictures and a suggested "required information" below

    Thanks in advance for the help…….

    (Pictures further down in post)


    - 1/2 Shiva Shanti (SS) and 1/2 unknown free seeds from seed-bank
    - Indica-Sativa hybrid mix
    - 8 plants currently
    - In vegetative stage for 4 wks
    - Indoor grow
    - Soil grow media
    - Mix is ECOgrow organic soil from Home Depot (hypnum peat, forest products, compost,sand and perlite) with 2 inches extra sphagnum moss @bottom of pot - very heavy soil(regret?)
    - Plastic pail about 4 gallons w/2-3 holes at bottom for drainage
    - Single 600W Metal Hydride conversion bulb - on 24hours during vegetive stage - will switch to HPS during flowering - lights approximately 24-28" away from top of plants
    - Fan cooled / 160 cfm bathroom fan @ ceiling with double intake on floor pair of 5" computer fans
    - Room temp averages 75degrees with lights on - fan thermostat controlled
    - RH is 30-50 - when initially measured - broke my gauge so now don't know - dry I think because of lights
    - PH of water I use is 7.0 / ph of soil when measured with my cheap probe is 7.0-6.5 / probe doesn't correlate well with PH strips
    - I don't see any pests on plants - did notice a very small white bug on PH meter one day
    - Was watering every 2-3 days / but pushed it out to 5-6 days at this point - trying wet-dry cycle approach - maybe too wet soil?
    - Plants only 4wks, so no ferts 1st 2wks - then 1/4 diluted Miracle grow 24-8-16 once before found growers frown on it - tried Alaskan fish and dried blood tea while trying theory that leaf problem is N deficiency - now bought FF GrowBIG but haven't applied yet
    - Grow room is a basement closet approx 3'x3',8' - shelf in the middle top for growing - sump/ejector pump in lower area - so not using 1/2 space - upper half of room is reflective mylar covered walls, ceiling, door - oscillating fan inside moving around air.










  2. #2
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    Re: Pics of sick plants - please help diagnose

    hey there. first off

    I would start by checking out Cannabis Plant and Pest Problem Solver - Pictorial

    several pics look like different problems,, but looks like ph issue...

    also, you mentioned that drying it out casued it to be worse.. maybe letting it get too dry? check ou tthe watering section of that thread as well..

    someone posted a great pic of a ph chart,, I will have to see if I can find it for you...

  3. #3
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    Re: Pics of sick plants - please help diagnose

    here are a couple of links to interesting posts

    http://www.420magazine.com/forums/jo...ml#post1099699

    I'm still looking for the others...

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    Re: Pics of sick plants - please help diagnose

    Could very well be poor drainage. You may need to repot with a better soil. My choice is FFOF with added perlite and 2 cups dolomite lime per bag of soil. Feed with water only until all looks good, then slowly add nutes to feeding.

    You also need to get a decent ph meter. Feeding mix/water should be 6.3 to 6.8.



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    Re: Pics of sick plants - please help diagnose

    I'll bet anything your PH is wrong. I started with a cheap PH meter. I believe the Milwaukee 6600. My plants looked like yours. I finally bought a more expensive meter and for the last three months, my plants have looked great.

    I'm 95 percent sure it's your PH of the water. Use 6.5 for soil and things will look a lot better.

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    Re: Pics of sick plants - please help diagnose

    Thanks for the expert advice - GREAT forum....

    Seems that PH and a new meter are the consensus...

    FOLLOW-UP question>

    Pretty clear how to measure the PH of the water or solution - BUT

    To investigate problem further - should I measure the PH of the runoff water after watering?

    OR how do you measure the PH of the soil (if not with an unreliable cheap soil meter)?

    How do I determine that PH is @ nirvana for each plant?

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    Plant and Nug of the Month Winner (July 10') Hogdady's Avatar
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    Re: Pics of sick plants - please help diagnose

    Quote Originally Posted by gfrombee View Post
    To investigate problem further - should I measure the PH of the runoff water after watering?
    absloutely, positively yes

    OR how do you measure the PH of the soil (if not with an unreliable cheap soil meter)?

    How do I determine that PH is @ nirvana for each plant?
    The ph of the soil will be reflected in your runoff ph. You will need an accurate ph meter for this. If your runoff is equal to or close to (within .5) your feed water, then your soil ph is tits. If not, you will have to amend the soil.



    “Who are you to judge the life i live
    i know i'm not perfect and i don't live to be.
    but before you start pointing fingers
    make sure your hands are clean.”
    ― Jimi Hendrix





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