Can someone explain pH adjustment ratio's to me?

Discussion in 'Growing Marijuana Indoors' started by Suppa_K, Sep 29, 2010.

  1. As in, if I want my soil pH to go from say 6.0 to 6.8, what level of pH should my water be at to bring it up to that level, what are the ratios if there are any. Lets say the water is 7.0 for this example.

    Basically how does pH level in water correspond to pH level in the plant, does the water adjust the pH to what level it is depending on if your going up pr down.
  2. It is hard to make guestimates on pH shifting.
    It really depends on the amount and type of buffers in the soil.
    Buffers are substances that resist pH change.

    Example with lowering pH in a soil with a lot of UP buffer - add acid, no change .. add more acid, no change, add still more acid and still no change, add a little bit more acid and get a big change.

    So your answer is - trail and error - start small and move in baby steps.
  3. Your ph will get low because of acidic salts from nutrients building in the soil. To remedy this you need to flush them out with 7.0 (give or take a few tenths, optimally give) and when you water (or feed) make sure its in the same range. I always water and feed with 6.7-6.8 water and flush about once a month if needed.
  4. I don't think anyone is going to be able to say something like "Add exactly x of y ph water."

    But generally if I want to raise PH I just added distilled until my run off is where I want.

    I never have a problem with two high.
  5. Play with your meter :eek: and just use a very small amount at a time and you will catch on quickly. :smoke:
  6. #6 Suppa_K, Sep 30, 2010
    Last edited by a moderator: Sep 30, 2010
    Ok, my water is deffinitely too high, its ranging at 8.3, so does this mean I want to lower it to 6.8-7.0 to raise my pH level which currently is 6.0 on one of the plants that is doing the worst.

    And judging by size should I transplant now? I was leaning towards yes, and the new soil may adjust the pH since I did use some older soil for these.

  7. Don't worry about your water being too high or too low, the only thing you worry about is your runoff. For example, if your water going in is 8.3 but your runoff is 6.0, then you need to raise your pH so the water going in, even if it seems high, obviously isn't high enough.
  8. The change is that quick..? I would think I wouldnt be able to really know the true adjustment until the next time I tested after I tried to raise it.

    I am not completely sure if its water, this is my second grow and I have grew a few others that I didnt stick with and all of those responded well to the water.

    I think it could be the strains, I have never delt with name strains before just bagseed.
  9. You are overwatering, you need to try less and get that water at 6-6.5.
  10. If you havent transplanted yet, get that dolomite lime shit, I've heard it balances the ph in the soil to around 7 throughout pretty much the whole grow.
  11. Well im kind of getting contracdicting answers here, so just keep watering with my 8.3 water or lower it to the 6.5-7.0 range? I am a little skeptical to try to add it to these small plants at this time, I messed around with the pH on my other more mature plant and it set it out wack really bad, its still recovering.

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