late in flower - when to drop P supplement?

Discussion in 'Coco Coir' started by LawlessNoOhm, Mar 17, 2012.

  1. growing in pure coco. It's a 10 week strain that will be chopped on May 4th (the 78th day since 12/12 flip)

    I am wondering when P should be cut to prevent a harsh product. Normally I would cut P 10-14 days before chop, give it light nutes until 7-5 days before chop and molasses the last 7-5 days and flush the shit out of them. But normally I dont calculate ppm so I dont know what my ratio was. (It could have been >100 I used to over do it...)

    For the past 3 weeks ppm RATIO has been this:

    N 75
    P 87
    K 228
    Ca 63
    Mg 83
    Fe 4
    Mn 0
    Si 77
    S 46

    I emphasize that this has just been the ratio because some feedings are full strength (ec 1.2-1.5) while others are EC 0.4-0.8 to flush

    When I keep the same nutes but drop my P supplements my ratio becomes:
    N 66
    P 28
    K 163
    Ca 63
    Mg 83
    Si 77
    S 46
    (recommendations to change this? Drop Ca and N?)

    Base nutes are Jacks Hydro, I've heard it doesn't lead to a harsh product..but then again I've heard the sky is blue because the ocean reflection :rolleyes:
    and P supplement is b'cuzz 13/14 and an off brand phosphorus supp (5-50-17)
  2. IMO cut everything besides the b'cuzz. if that
  3. #3 colafarmer, Mar 17, 2012
    Last edited by a moderator: Mar 17, 2012
    Nitrogen is the bad boy that leaves a chem taste on your pallet and contributes to harsh smoke and burning quality.
    Would not give any fert especially with nitrogen the last two weeks except for the molasses.
    Check you ppm of runoff before you start the flush and flush real good with plain water until your ppm(EC) of runoff lowers to match water used for flushing.

    I think it also helps taste to harvest 24-48 hours after a dark period or, when the lights come on after their dark period...This is when the terpine level is the lowest, which contributes to aroma, taste and a more noticeable frosting of the buds...

  4. highest not lowest. but yea good info colafarmer, spot on!
  5. My method is to cut all nutrition about 10 days before harvest. Phosphorus supplements are usually axed around 10 days before that. The last 20 days on a 70 day flowering period are generally very low level feedings. I prefer to let the plant consume what is present.

    I imagine that it might take a little finessing. I definitely wouldn't run my P-Supplements after the 2 weeks to harvest mark. The actual date definitely depends more on the appearance of the plants (how much of the element I think they are really using is an important factor) than anything.

    Excess Phosphorus will result in a blacker ash when you burn the cannabis. Regardless of when you do cut out the supplements it is still very important, IMO, to utilize the CEC of the coco to draw excess elements from the plant into a freshly flushed media. This process although slow and not extremely efficient will remove whatever you have added to the system as long as it has enough time to do so. I think that a grower could, technically, feed at full strength in coco up to about 10 days before harvest then flush, flush, flush, and get a clean final product.
  6. thanks for the tips everyone, the last week has been 1/2 strength nutes and the final flush begins today :smoke:
  7. Use a lot of PK during flowering and usually flush two weeks before the harvest and water only after that..
    My last Ganesh grow I waited 7-10 days before harvest and flushed with clearex for the first time....This pot smells great, kicks ass but, not a good taster...

    Anyway went to do some blood work at VA and my potassium level was so high I had to retake that part of my lab work...Finding out tomorrow whats up.
    Thinking I been injesting potassium into the blood stream...Guess I will need to fess up with my doc....

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