Mag def? not sure

Discussion in 'Marijuana Plant Problems' started by fruits of labor, Feb 8, 2018.

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    fruits of labor

    fruits of labor Active Member

    Everything from searching points to mag/cal def but im beginning to question..added calimag but issue remains...could it be other things? I know i havent posted specs of everything just looking for a 1st opinion..only happening to one of the 12 i have going....all treated the same
     

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    fruits of labor

    fruits of labor Active Member

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    dtl420

    dtl420 Well-Known Member

    It definitely looks like Mg to me. The leafs will only recover if they're not too far gone. The leaf from the first pic won't recover as it is showing some necrosis. If the symptoms stop spreading then you're good.

    Is it continuing to progress? What medium are you in, and what kind of nutrients are you using?
     
    Blitz35 likes this.
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    Blitz35

    Blitz35 Well-Known Member

    That's textbook magnesium deficiency. There is no such thing as a 'cal/mag' deficiency! its one or the other, and if you are lacking magnesium because you have too much calcium that's locking it out, then adding cal mag will only further exasperate the problem. What are you feeding and what is the source of water? If it's tap water, find out the composition of it from an online water report. What are you growing in? Do you have a pic of the entire plant visible?
     
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    Tiffj

    Tiffj Well-Known Member

    Agreed! Some tap water is low and Mg! I had the same problem! Need to add a dose of Epsom salt next feed and maybe just a couple after also! Fixed it right up for me! Leaves stopped discolouring, I just added like 1/2 teaspoon with every litre of water after dissolving it in hot water :)
     
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    frizfrazjaz

    frizfrazjaz Well-Known Member

    So adding cal/mag will only make a mg def worse. Is that what you’re saying?
     
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    Tiffj

    Tiffj Well-Known Member

    If your in soil go with Epsom salt, unless you can find an organic calmag but to be honest it looks as though you need Mg and not Ca
     
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    frizfrazjaz

    frizfrazjaz Well-Known Member

    Will Epsom dissolve in cold water? I don’t need the ppm’s coming off my hot water tank.
     
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    Tiffj

    Tiffj Well-Known Member

    Just a trickle of hot water in a mug or something, dissolve the Epsom in giving a good stir then add that little bit of hot water to your feeding water, simples!
     
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    dtl420

    dtl420 Well-Known Member

    Epsom salt is 100% water soluble. It will dissolve quicker in hot water (like any other salt) but it will also dissolve into cold water as well. Typically your hot water is going to be "harder" than your cold water from the tap due to evaporation, so it's better to use the cold tap water in the garden. I do dwc and I like to add some tap water to my reservoir to help buffer the pH. The higher the tds content the less pH swings.
     
    frizfrazjaz likes this.
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    Blitz35

    Blitz35 Well-Known Member

    If you're mg deficient because of a lockout caused by an excess amount of calcium, then yes, adding cal-mag won't help as there is generally more calcium in cal mag than mg. One way to tell, as it's not terribly easy to see a calcium toxicity, is to check the medium (assuming it's not dwc), and if the dirt is overly 'loose', then you have enough or too much calcium. A medium that has a closer ration of cal:mg, will be more compact/dense as magnesium is a smaller ion than calcium and pulls your dirt closer together where calcium is larger and 'spreads' it out. With that being said, the overall ratio you want to maintain, if growing in heavy dense clay soil, is about 7:1 cal:mg. In looser/sandier soil, it can be as low as 3:1 cal:mg.
     
    Last edited: Feb 10, 2018
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