Raising and Lowering pH of soil

Discussion in 'First Time Marijuana Growers' started by zombieSHROOM, Aug 3, 2011.

  1. Ok, I've read all the articles on pH and what it does for the plant, and how it works, but i still cant understand the process of actually changing the pH of the soil.

    This is how I have it figured out:

    Right now the run-off I collected from my soil is 5.0 (I know, I need to go higher, that is why I went and bought the test kit, I had suspicions the pH was off).

    So I have 1 gallon of distilled water and some GH pH Up. The pH of the water is around 8-8.5 (This is the water that I've been watering with the entire time).

    Do I raise the pH of the water 1.5 levels (I'm looking for a soil pH of 6.5) and continue to water with it and it will adjust itself? The pH Up that I got is in concentrated form, so its a powder. How much do I add to 1 gallon of water to raise it? Or can I just gradually add a little bit and keep testing it?

    Sorry this is SO newbish :eek: but this is my first grow xD Thanks for ANY help blades!!
  2. What kinda soil

    Dolomite lime....from a hydro store...sprinkle and water...

    Ph problem fixed in about a week or two
  3. Ocean Forest soil

    I already purchased the pH up and down so I really dont want to go spend anymore money.
  4. How much fertilizer have you been giving your girls.. Ocean Forest has a lot of nutes to begin with. The low pH may be the result of a buildup of nutrients??? what symptoms are you having? Pics?
  5. No ferts.

    Nothing but Ocean forest and Water.

    Yellow flaking on the leaves, drooping tips on lower leaves, stunted growth.
  6. Cal-mag deficiency.

    Don't waste your money on ph up/down for soil, it's useless. Soil PH is regulated through chemical reactions between hydrogen and aluminum (acidic), and calcium and magnesium (alkaline). Since your plants take up more cal-mag than they do hydrogen and aluminum, your soil will drift towards acidic. If you try to regulate the ph with the water you pour through your pots, all the helpful minerals just pour through your pots, giving you a temporary fix.

    PH can be stabilized in this manner but like I said, it's a quick fix and needs to be repeated. Adding lime to your soil is a long-term solution to many problems, including PH.
  7. Thank you!

    So until I can afford to get some lime, the pH Up will help me temporarily?

    Like, here is how I am thinking:

    The normal pH of the water I use is 8.5+
    The pH of my soil is 5.0
    If I add the pH Up til it raises the pH 1.5 points , and use it to water my plants (Obviously staying consistent with watering) will that balance the pH to 6.5???

  8. Hey, I am running the ocean forest also... I transplanted from 32oz containers into 3gallon containers the same day I switched to 12/12. Took them 5 days to dry out and need a watering, which i gave 900 ppm of big bloom, tiger bloom, open sesame and Cal/Mag.... 4 days later I am showing a potassium deficiency. From what I can gather, the potassium should be in the soil, but possibly locked out due to too much calcium? I looked at the ingredients of the fox farm soil and it said it has a high level of calcium, so maybe I just began supplementing too early??? Before the roots got a chance to set, and suck up the initial calcium?

    Zombie, sorry for stealing your thread but its right on topic!:D:wave:
  9. It seems strange that your distilled water has a pH of 8 - 8.5, and also strange that this would cause the soil to become so acidic. What kind of pH test kit are you using? How old is the plant?

    Theoretically, if you want to raise the ph from 5.0 to 6.5, you would water with ph 8.0. But, that's what you've been doing. As others have said, soil tends to do what it wants to do, and it doesn't change quickly. The dolomite lime isn't expensive (just don't get hydrated lime). But I am questioning the results of the pH tests.
  10. I agree with vash distilled water should be closer to 7 do you have the ph test liquid to adjust the accuracy of the meter.
  11. Powdered dolomite lime comes in a 40 lb bag at home depot for $3.50, and it's great.
    I didn't start getting good results until I started adding lime to my OF.

    I wouldn't use that water. 8.5 water is not something you want to give your plants. It's got too much calcium in it (hard water). It won't hold much nutes either, if your water already has dissolved solids in it then adding more will lockout nutes to your plant, even if you use a small dose. The Mandala link I post below explains why. Recommended ec for soil is .7, and if your water is already say... .8, then adding even a small dose of nutes will cause lockout.

    Hope this helps!!

    Mandala Seeds recommends .65-.7 EC. I try not to discuss ppms because each manufacturer uses a different formula for converting ec to ppms.

    You probably hit the nail on the head though, when I used cal-mag, I waited till they showed signs instead of giving it right away. Now I use lime and don't worry about it.

  12. I'm not really sure what you are asking me.
  13. #13 BeZtoken, Aug 3, 2011
    Last edited by a moderator: Mar 15, 2016
    Well my ph meter has a little screw on the back to adjust the accuracy you put the meter into a buffer solution and if its off you adjust the screw until it reads 7.0. Idk if all meters are the same. Did yours come with a little screw driver? I'm adding a pic of the solution.

    Attached Files:

  14. Ok here's an update to what I am doin:

    I purchased a 40 lb. bag of Lime
    I lowered the pH of the water from 8.0 to 7.0
    I sprinkled a handful of lime into each pot, and watered with the lowered pH water.

    I am going to check on them in about an hour or two and I'll report any differences.

    Hope I did this right!!! :)

  15. I've never bought it from a hydro store and not likely to, but at HD or Lowes it's ~$5 for a 40lb bag.

    If $5 is too much to fix/end your pH problems ...............


  16. Give it a week or so to work.

    It WILL work, but not in 'hours' or overnight. Don't be impatient. That is the quickest way to fuck up that I know of, other than *good ideas* after smoking. LOL

  17. you only needed a tablespoon or so per cubic foot of soil... a 40 pound bag would last a life time...

    and I should have said powered dolomite lime... and like the previous poster suggested home depot has some super cheap stuff... but I figured if you talked to a hydro store they could have spelled things out

    but to answer your question about upping the PH of the water to up the PH of the soil, yes that would work... most only do this for small fluctuations in PH

    or you could run five gallons of PH'd 6.8 water threw your soil and that would work as well.... called flushing...

    then you could have used the lime and that would have stabilized your soil to the proper PH

    you keep saying that your distilled water is close to a PH of 8... it should be closer to 7... like the previous posters suggested... this leads me to believe your PH PEN is toast or your trying to use the dropper system and calling it a pen.... if your PEN is getting the correct PH you should consider getting another water source(is this wal-mart distilled water?)

  18. Good way to read the post before yours!! GOOD JOB! lmfaooo

    And for everyone else, after one night of the lime/using new water they already look like they are responding!! Thanks for all the help blades, ill keep everyone updated!!
  19. Wish the lowes/home depot had powdered lime by me. all they have is the pellets which I bought, but havent been able to include in my soil. Im waiting for my next grow to incorporate in the soil before planting
  20. Grind the pellets into powder?

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