Soil runoff ph at 5.3

Discussion in 'Growing Marijuana Indoors' started by HomeDePot, Apr 1, 2012.

  1. First I tried growing several times with pro mix... That didn't go well. Runoff water was always way to acidic as low as 4.8. Tried upping water ph to 12.0 like a mad man but that didn't really affect anything.. Not sure why.....
    Second I tried growing with soil.. Indoor outdoor premium potting soil by Schultz. Same problem as before! The runoffs way to acidy
    Now I'm considering hydro!!! But can't afford it yet and plus it's pissing me off that I can't get this to work.
    I'm sure there's a simple fix that I'm not doing!
    Any advice would be grand,
    Thanks in advance
  2. I know soil runoff isnt a good way to measure ph...they recommend doing a 5 parts dirt to 1 part water slurry then let it sit for an hr before testing ph and that should be your real ph...try hempy buckets if you cant afford hydro right's just 100% perlite and works like hydro
  3. Hempy buckets are fucking awesome. Definitely check it out - way easier than soil.
  4. My bad it's one part soil to 5 parts water

  5. When doing this, should I use pH neutral water, or does it matter?
  6. your run off should be around 6.5-7.0 in soil, are you sure your ph tester is accurate? what is the ph of the water you are putting in? are you adding nutes?
  7. I'm assuming they want as close to it as possible like distilled or ro was an article about why fox farm soil reads acidic and fox farm replied saying if you do the slurry it should come out around 6.5 even though the runoff says 5.8....wouldnt hurt to try
  8. @Panda85
    The ph of the water I'm putting in has ranged from 6.5 all the way to 12.0 in a desperate attempt to bring the soil ph up to something less acidic. I use RO water.
    I have buffering solutions one at 7.0 and another at 4.0 and I use them to calibrate the tester so yes the tester is accurate.
    When I water with a very high ph the runoff stays more or less the same... In the low five range. So I know that adding ph up to the water dose nothing for the soils acidity.
    Is there something I should be adding to help up the ph? Dunno but any advice would be amazing
  9. @Panda85
    The ph of the RO water I use is about 6.3
  10. Yea make it 7 so it's can top dress with dolomite line but it's slow do the plants look if they look fine I wouldnt get too worried
  11. They look like shit.. Very sick looking. What ive noticed is that whatever water ph I put into the soil or even promix comes out more or less the same so for example I put 7.0 and it comes out 5.3 or I'll put 8.0 and it still comes out 5.3.. I then tried 10.0 and 12.0 but it still comes out 5.3
  12. How much water are you using when your checking the run off ph? IMO you could try flushing it and it should end up at the ph your looking for. Use three times the amount of water that your plant is in. Ex, if it's in a 5 gallon bucket then flush with 15 gallons of water. Make the water the ph you want to end with. 7 for soil?(I use coco) This should get you evened out.
  13. Add powder dolomite lime...problem solved. Common sense in a soil-less sphagnum peat gross substrate...degrades rapidly cause the soil to become more acidic...
  14. @Kesey
    Powdered dolomite sounds good. I'll get promix and try it out. Whats a ball park range to how much dolomite to mix in... Oh and I wouldn't know where to find powdered dolomite. Any suggestions?
  15. Havent heard of that before. I use Ocean Forest and Light Warrior for seedlings and I can put in tap water that sat out for a day or two ph`d at 6.5 and get a run off reading right around 6.5. The same when I nute feed using Advanced Nutrients. I use a Blue Lab Combo meter.

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