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Thread: Help diagnosing leaf yellowing / burn or something on Coco please

  1. #1

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    Default Help diagnosing leaf yellowing / burn or something on Coco please

    Soil, hydro or coco?: Canna coco premium

    Strain: Big bud, Sour Diesel

    Photo or Auto: Photo

    Plant age: Small ones potted from clone 7 days ago, bigger ones potted 21 days ago.

    Pot size: 3L

    Has it been repotted? and when?:

    Soil type: Coco as above

    Nutes or additives used and how often for soil: For Coco:

    Following the feed guide
    My water in my region is 0.1 EC
    Topped up to 0.4 EC before applying Canna nutes
    Final EC was 1.7

    - Canna coco a/b
    - Canna coco Rhizotonic
    - Canna Canazym
    - Canna calmag

    Air temps / humidity:



    Res temps (max min): Not measured, would be close to ambient tent temp in graph above.


    Lighting type and wattage (hps, led, cfl):

    450w full spectrum LED quantum board
    DLI has ranged from 20-30 - ramped it up, then dropped it back down when they looked pissed off

    Light schedule: 18/6

    PH level: 5.6 - 5.8

    EC (hydro and coco only): 1.0 to 1.5

    Background EC. : 0.1 - bumped up to 0.4 with calmag due to local water

    Feed schedule and nutes (for hydro and coco) - As they are in veg feeding them based off pot weight rather than daily, every 2-3 days at the moment until they need a feed.

    I THINK my pH meter might have been out of calibration, I recently bought a new one which shat itself and wouldn't even calibrate, but I gave the plants a feed using it to pH my nutes, I was drunk and lazy at the time so was like fuckit I'll just use it out of the box it can't be THAT off.
    I then used it again the next day while I was stoned as shit and was like wtf why am I using SO much pH up.. to get the pH up to like 5.6-5.8.... hmmmm so it could of been a lot higher.

    Long story short the pH could have been WAY out of wack like up at 7.0 or something for a few days.

    I've given them a feed with corrected pH yesterday but they haven't really recovered.

    Not sure..






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  3. #2

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    Give them a flush with plain "correctly" ph'd water then a light nutrient feed and they should perk right up.

    Also coco needs watering EVERY day, it keeps it aerated. It also helps keep the rootzone at the ideal balance for PH and feed levels as you are effectively flushing and resetting the zone daily when you feed.

    Dry coco can be very hydrophobic (repels water) which will exacerbate any issues.

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  5. #3

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    Quote Originally Posted by Mac View Post
    Give them a flush with plain "correctly" ph'd water then a light nutrient feed and they should perk right up.

    Also coco needs watering EVERY day, it keeps it aerated. It also helps keep the rootzone at the ideal balance for PH and feed levels as you are effectively flushing and resetting the zone daily when you feed.

    Dry coco can be very hydrophobic (repels water) which will exacerbate any issues.
    Yeah true makes sense prob not worth trying to correct it. Flush it is.

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  7. #4

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    Agreed with Daddy Mac. Daily fertigation with proper pH.

    Your temps are trending a wee bit low as well while your humidity is spiking. That makes it real tough for the plant to sweat. They don't sweat they don't drink. They don't drink, how can they get that sweet nutrition?
    (Cheers Blue61)

    May want to raise your VPD. 1.0kPa should be about right at this stage imo.

    Cheers
    B


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  9. #5

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    A pH range of 5.8-6.2ish is much better than 5.6-5.8, calcium can be real difficult to uptake below 5.8 pH and you'll need more in flower.

    J

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