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Thread: Brown + dying leaves, been stuck trying to solve this

  1. #1

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    Default Brown + dying leaves, been stuck trying to solve this

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    Leaves from GSC, 46 days from flip, grown from feminised seeds in soil, 20l/4gal pots under 600W HPS.

    I use RO water with Shogun nutes: 1ml/l calmag and 2ml/l bloom, keeping water ph in that 6.2-7 range

    These leaves come from near the top of one of my plants. Cut them off to get proper lighting on them for the picture.

    This is my second grow and the second time I've had this problem, both times it's started around week 5 and I've tried all kinds of recommended fixes. It started slowly with speckled brown spots on the leaves which progresses with the leaves eventually turning completely brown and crispy.

    In the first grow i made a mistake of not watering properly to run off and so going in to this run I didn't expect this issue again. I get a good 6-800ml run off from each plant every feed. I've tried a complete flush last week which did not stop the spread of the problem. I thought it might look a lot like a calcium defficiency so I stopped RO'ing my water and kept the same 1ml/l dose of calmag in the last feed 4 days ago but the problem keeps spreading. Before I water them again I really want another opinion on what i should feed them to sort this out.

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  3. #2

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    I see people post up about not PH'ing your feed when growing in soil mate.

    Maybe something to do with that.

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  5. #3

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    That’s a pretty hefty pH range. 6.2 is 8 times more acidic than 7.0.

    This looks very much like a pH issue to me.


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  7. #4

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    Agree with the above, soil contains lime and natural elements to buffer Ph of any feed you put in. If you are then also adjusting the Ph of that feed, your more than likely knocking out of the range it requires for macro elements.

    Think of growing in soil as growing in the garden, you don't Ph rain water, its no different for indoor plants.


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  9. #5

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    Shit I've been going really wrong then. Would my fix be to flush with either RO or reg water next feed and then continue with normal nute schedule but without adjusting pH? My pH after adding nutes is usually about 5.6 and I was always thinking this was far too low.

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  11. #6

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    Quote Originally Posted by TonyAdams View Post
    Click image for larger version. 

Name:	IMG_20220101_230502.jpg 
Views:	34 
Size:	2.20 MB 
ID:	413895

    Leaves from GSC, 46 days from flip, grown from feminised seeds in soil, 20l/4gal pots under 600W HPS.

    I use RO water with Shogun nutes: 1ml/l calmag and 2ml/l bloom, keeping water ph in that 6.2-7 range

    These leaves come from near the top of one of my plants. Cut them off to get proper lighting on them for the picture.

    This is my second grow and the second time I've had this problem, both times it's started around week 5 and I've tried all kinds of recommended fixes. It started slowly with speckled brown spots on the leaves which progresses with the leaves eventually turning completely brown and crispy.

    In the first grow i made a mistake of not watering properly to run off and so going in to this run I didn't expect this issue again. I get a good 6-800ml run off from each plant every feed. I've tried a complete flush last week which did not stop the spread of the problem. I thought it might look a lot like a calcium defficiency so I stopped RO'ing my water and kept the same 1ml/l dose of calmag in the last feed 4 days ago but the problem keeps spreading. Before I water them again I really want another opinion on what i should feed them to sort this out.
    Looks like nutrient burn to me when you have dark green leaves with discoloration. What EC are you feeding them?

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  13. #7

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    Quote Originally Posted by TonyAdams View Post
    Shit I've been going really wrong then. Would my fix be to flush with either RO or reg water next feed and then continue with normal nute schedule but without adjusting pH? My pH after adding nutes is usually about 5.6 and I was always thinking this was far too low.
    Are you in the UK, Tone? If you are, then tap water is almost certainly fine but it would help to know if the water is hard (high in mineral content) or soft (low in mineral content) - should be able to find yours on the water board's site via a postcode check - post the results here if you want a quick analysis.

    Broadly, if you're happy drinking from the tap, then crack on with that. Fiddling with pH in soil rarely has a good outcome, IMO.

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