Is there a way to regulate pH in the middle of the crop?

Discussion in 'Sick Plants and Problems' started by Vancho, Oct 30, 2023.

  1. What if you had a soilless mix buffering at 5.5 and then you add too much dolomite a the point now your mix is buffering 6.7-7.0

    But you were aiming 5.8-6.2

    Is there a way to lower your soilless to 6.2 adding something to the watering? since I cannot mix anything on the substrate right now at flowering week 2. No matter if my nute solution is 6.0 or 5.5, the runoff is always around 6.7.

    I'm starting with some deficiencies already. Still have 6 more weeks of flower.
    Is there a way to fix this?

    Thanks in advance
     
  2. You could cut some lemons up and drop them in your water container, this will reduce the PH over time (organic), or use ph down.
     
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  3. You will need to neutralize the base (ie. lime) with an acid. If you use nitric acid, you will produce calcium nitrate, but you don't want that in flower. You want to mix phosphoric acid to increase phosphorous. That is usually what manufacturers use as pH down.
    If you feed at 5.5, or even lower, and keep doing it, it will neutralize, but it takes time. May want to look over this tread:
    The Fast and Furious Flush'o'matic
    I wrote it up for seedlings, but the same concept for larger plants. The manifold design would obviously have to differ. If the pot is large enough, then I think one might not even need a manifold/lid.
     
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  4. that is a piece of information! thanks.
    you think phosporic acid solution would solve the issue with time? i will start next watering with that
     
  5. If you feed at 5.5, or even lower, and keep doing it, it will neutralize, but it takes time.
    When the runoff pH starts to get near where you want it, you want to increase the pH of the fertigation solution.
     
  6. so flushing with 5.5 pH phosporic acid solution would solve the unbalanced media within 24hs?
     
  7. hmm... what I recommend is to continue feeding using low pH solution, explicitly wrote fertigation solution, which means fertilizer included.
    But, if you are doing a flush, like in that thread, using a vacuum, then just use water + 5.0 water. Run it through and check the pH. Adjust the pH back to 5.0 and run it through again. Repeat but adjust to 5.5. Repeat until you get the proper pH (6.0). Then make up a good nutrient solution at pH 6.0 and flush it again.
    I'd use a vacuum, otherwise that process will take a very long time and your media will get water logged = bad. When I use the vacuum method, I run it until the excess solution is cleared, leaving good amounts of oxygen for the root system.
     
  8. yep the pot is 7L so it would be necessary a big setup for the vacuum. I guess my option is to start feeding at 5.5 until the lime gets neutralized. Also, I have 6 plants in this situation.

    Thanks for the reply!

    edit: I already bought the phosphoric acid
     
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