Purple spots on leaves / Northern Lights

Discussion in 'Marijuana Plant Problems' started by Googlebot, Jan 19, 2013.


    Googlebot Member

    hi folks

    Ive found some purple spots on my leaves. Also u can see yellowing and other horror in my grow but thats another story. They were root bounded and had to transplant them in day 15 in Flower (It was around 3-4 days ago). Anyway they seem to be ok now except this purpling issue. My guess is underfeeding cause they still get just 2ml/L BioBizz Bloom.

    Set up:

    Strain: Northern Lights
    Light: 250W CMH
    Medium: BioBizz All-mix Soil
    Nutes: BioBizz Grow, Bloom and Unsulphured molasses (cause my topmax went off)
    Pots: 4Gallon

    If you think thats not enough information please have a look at my journal. http://www.rollitup.org/grow-journals/603446-250w-cmh-northern-lights-organic.html

    Day 18 in Flo
    image007.jpg image006.jpg image005.jpg image004.jpg image003.jpg image002.jpg image001.jpg

    ynkessuck247 Active Member

    In the first picture they would be more black spots because it is necrosis. My guess is it might be Mn toxicity. And the other pictures, it is difficult to tell but looks like it could be P deficiency.

    Whats your temp differential ?

    Googlebot Member

    Hi mate, thanks for your reply! Its weird cause i never gave them extra magnesium. Although, i add 1 tbsp unsulphured molasses (to 1 gallon of water) every watering since i put them in Flo. Im not sure how much magnesium it contains.
    Temp is 18°C at night and 21°C when light is on.

    Uzergu1de Member

    P deficiency!! Purple leaves yellowing with necrosis on tips... My money's on that!

    ynkessuck247 Active Member

    i meant Manganese Mn

    SpectatorFernFirm Active Member

    Man my pride and joy is looking EXACTLY like yours :(. I transferred mine to a new 5 gal bucket with fresh new water and nutes in hopes to stabilize her but I'm super worried something has gone terribly wrong! So you guys are saying just up the nutes a bit?

    Googlebot Member

    its kinda confusing pal

    ynkessuck247 Active Member

    its not. it all could be related to Manganese toxicity !! lol

    ynkessuck247 Active Member


    read that and you will see that unsulphured molasses contains high amounts of manganese.

    "Manganese, a trace mineral, is very high in content with unsulphured blackstrap molasses. Manganese ions function with a number of enzymes, and are essential to combating unusual free radicals. Like magnesium, manganese also supports cellular absorption of nutrients..."

    theres your problem my friend. cut back on every watering, and try applying it every other watering.

    420tric likes this.

    Googlebot Member

    wow man u really know whats going on here. Ill cut back with molasses. Thanks a lot mate!

    bigedbowman Member

    A hommie, sometimes when plants get cold or really mature they may purple. The yellowing is from being in flower, slow down and watch
    somethN else other than your plant. They all look healthy man, relax. If you don't like the yellowing then cut the leaves. You shoud make a journal and
    read it from time-to-time. Not every change is negative, think about "Fall" and "Autumn" trees change colors mane, part of nature bro.
    Just make sure you look for pests and you'll be fine bro.

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