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Phosphorus deficiency?

Discussion in 'Marijuana Plant Problems' started by leoshitz, Sep 10, 2017.

  1.  
    leoshitz

    leoshitz Well-Known Member

    IMG_2759.JPG IMG_2760.JPG IMG_2761.JPG What do you think?

    Indoor
    Soil
    QB x4 lighting
    Canna nutes
    Good ventilation
     
  2.  
    XipXipXoom

    XipXipXoom Member

    Possible deficiency due to root rot from soil being kept too wet. Wet feet. Does your soil have much perlite in it, and do you put a layer of hydroton, rocks or perlite on the bottom to improve drainage? How is your containers drainage?
     
  3.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member

  4.  
    Rob Roy

    Rob Roy Well-Known Member

  5.  
    Buba Blend

    Buba Blend Well-Known Member

    Tell us what soil you are using.
    How often you water?
    How big are the pots?
    My 1st feeling is lockout from watering issues. The leaves also look like they have a weak green color also.
    Pictures of the whole plant would be nice.
     
    MichiganMedGrower likes this.
  6.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member

    The rust spots turning into necrotic patches.

    Did you look at the pics in the link? It has good troubleshooting info too.
     
    Orlando737 likes this.
  7.  
    Rob Roy

    Rob Roy Well-Known Member


    Thanks for posting the link. I didn't look at the pictures in the link initially, as I agreed with you and thought his plants may have a calcium deficiency.

    He might consider checking his water ph, might be where the issue arises from.
     
    cindysid and Orlando737 like this.
  8.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member

    I am having the same issue right now in my own garden. My well water has been stable at about 150 ppm mineral content for over 2 years at the house I bought. Now with the drought this summer the lack of running ground water has lowered the minerals to only less than 100 ppm.

    Even the minor calcium buildup is gone from my faucets. The hitch is the iron is still there and that may be the thing out of balance.

    I have implemented a couple ml's of cal mag for now. It may go back up with the end of summer rains. So I keep trying to re dial in like it was.
     
    medicated00420 and Buba Blend like this.
  9.  
    Rob Roy

    Rob Roy Well-Known Member


    Fluctuating well levels can create problems. I've had to manually apply PH down to water jugs in the past to get to the right level.

    As you probably know the wrong ph range can create lockouts etc. A well calibrated water ph tool can be very helpful.

    Good luck with your grow.
     
    MichiganMedGrower likes this.
  10.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member


    Thanks and yup my well is deep and stable and only dropped a bit comparitavely but it is the alkalinity that effects the medium not the source water ph.

    Mine is 8.0 ph and comes out of buffered soil at 6.3 or so every time.

    Now if it is over 250 ppm I would likely filter or add acid. I'm bummed at the moment after 2 years of no real issues.

    I may add a carbon filter to the well and see what I get.

    At least I have really learned all about calcium, magnesium and iron. :-)
     
    Rob Roy likes this.
  11.  
    Buba Blend

    Buba Blend Well-Known Member

    How many ppm's of cal/mag is that you are using? Did you use GO cal/mag +?
     
    MichiganMedGrower likes this.
  12.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member

    I just bought Botanicare cal mag+

    I'm already using pure Blend Pro.

    My well water was .3 ec for the last 2 years steady so I was caught off guard.

    It is now .2 and I didn't even notice the cal deficiency until week 3-4 flower.

    I can see the stress in veg now that I know to look. It's mild.

    So I have added 2 and 3 ml's to different plants and am waiting to see.

    Of course the least affected one seems to be recovering 1st. But some have the climbing fan leaf necrosis already.
     
    Buba Blend likes this.
  13.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member


    The weak green color is likely from the conflict calcium mag and iron out of balance cause.

    I have mis diagnosed this as a phosphorous or potassium deficiency starting for years myself.
     
    leoshitz likes this.
  14.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member

  15.  
    Buba Blend

    Buba Blend Well-Known Member

    Haven't heard from the OP since the original post, this isn't hi-jacking, is it?
    Anyway.
    I'm just finishing up a run of mediocre plants from an ro only run till week 4 in flowering.
    Had calcium deficiencies that were not from a lock out from what I could tell.
    When I added go cal/mag +, 100ppms, the deficiency stopped in its tracks very fast, sorta frozen in time for several of the plants as far as fan leaf conditions. If I did not give them the cal mag the fan leaves deteriorated fast.
    After the initial feeding of 100 ppms, I backed it down to 80 the eventually to 60 ppm's. Next grow I'll probably feed most plants 40 ppms from the start.
    I forget what medium you are using?
     
    leoshitz and MichiganMedGrower like this.
  16.  
    greg nr

    greg nr Well-Known Member

    I've seen that result from transplant shock. Not really a deficiency in the sense that it isn't in the soil, just that the plants aren't taking it up fast enough. Once the plants grew a bit, it went away and new growth was fine.

    Not saying it's not a deficiency, just that it can be caused by other things than soil levels of a certain mineral.
     
  17.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member


    Ocean forest.
     
  18.  
    MichiganMedGrower

    MichiganMedGrower Well-Known Member


    Absolutely!

    In that second link I provided from Grow weed easy they say under and Overwatering and salt buildup or overfertilizing or even too much calcium will block uptake.

    And iron and nitrogen are antogonists and need to be in balanced amounts.
     
  19.  
    XipXipXoom

    XipXipXoom Member

    It could certainly be from using RO water because AFAIK Canna nutes are designed for tap water, unlike General Hydroponics 3 part for example, which include cal-mag in their micro.

    My line of thinking on that growweedeasy link is where it says "Uneven moisture levels in the soil or growing medium." If the bottoms of the pots are always staying wet and only the top drying out, it could be the start of root rot.
     
    Last edited: Sep 13, 2017
    leoshitz and MichiganMedGrower like this.
  20.  
    leoshitz

    leoshitz Well-Known Member

    Oh wow thank you for the replies.

    I water with tap that I let sit for 24 hours so the chlorine dissipates. The soil is Up country from Fox farm. I mixed in quite a bit of pearlite. I have 3 different plants in the tent. Two look great (707 headband and Jack H) and the Blue Dream has the problem. I do not water to the point of flooding the pots. I will get more pictures in a few.
     

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