Raising PH of Soil

Discussion in 'Advanced Growing Techniques' started by DubLifePDX, Jun 21, 2015.

  1. #1 DubLifePDX, Jun 21, 2015
    Last edited by a moderator: Jun 21, 2015
    I will say now, I'm somewhat of a beginner. I feel a bit more confident posting this here considering I've recently caught the notion that some people don't really care about PH. 
    So here's the thing... Growing 4 girls outdoors, 1 is in a 25 gal smart pot, and 3 are in the ground. The smart pot has Fox Farm Ocean Forest while the 3 in the ground are just working with the soil that was there. They've been going for about a month now, and they all appear really good to be honest. No signs of deficiencies whatsoever. However, I got a BlueLab Soil PH Pen, calibrated it, and went testing, and all the readings I got were within 5-5.5. 
    So my question is; how do I go about raising the PH? I know I need to do it slowly over time, and I've seen some suggested methods of action, but I need specifics. I need to know what you used, how you used it, and results. How does one go about amending soil? 
    I've also been feeding with GH Flora Series every so often (maybe 2 times thus far, with watering in between as needed) and adjusting the PH of the solution using PH Up and PH Down. 
    Thanks for the help fellas. 
    P.S., the white power is diatomaceous earth, had pleasant results with it.


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  2. I wouldn't do anything.  Your plants look beautiful.
    Soil pH is dynamic.  It changes constantly.  It goes up, it goes down.  It's never stable.
    I think you'll find that if you take several more readings at different times, you'll find this to be true.  Take a reading just before you water.  Take one several hours later.  Take a reading right before you feed and then another several hours later.  And take several different readings from different spots around each plant.
    From Soil Chemistry by Bohn, McNeal, and O'Connor...
    Soil pH measurements can be ambiguous.  Two factors that affect soil pH measurements are the soil-solution ratio (or how much moisture is contained in the soil, my addition) and the salt concentration (available nutrients in the soil, added by you or not, my addition again).  Increasing either factor normally decreases the measured soil pH because H and Al cations on or near soil colloid surfaces can be displaced by exchange with soluble cations.  Once displaced into solution, Al ions can hydrolyze and further lower the pH.
  3. #3 DubLifePDX, Jun 22, 2015
    Last edited by a moderator: Jun 22, 2015
    Thanks for such a detailed response waktoo, much appreciated
  4. How did they come out?

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