Major PH Issue, Please Help!

Discussion in 'First Time Marijuana Growers' started by bgumskunk, Sep 18, 2010.

  1. I have been having a major PH issue and I'm not sure what to do. PH runoff when watering with PH neutral (PH =7) water is about PH = 5. This is in soil.

    Grow details

    STRAIN: Peacemaker, Nebula, Super Skunk
    INDICA/SATIVA: Indica/Sativa\t
    HOW MANY: 6
    IN/OUT: Indoor grow
    SOIL/HYDRO: Soil, Roots Organics potting soil\t (has a bunch of organic nutes in it and coco)
    POTS: Using 3 gallon fabric pots, just transplanted from 1 gallon plastic
    LIGHTS: 600 watt HPS, air cooled with ducting
    NUTES: botanicare
    Water: RO/DI
    ROOM: Cubby space ~4'x4'x4'
    LIGHT SCHEDULE: Was running 24/0 just switched to 12/12
    PLANT AGE: Started from seeds ~6 weeks ago
    PLANT SIZE: 15-20”

    Symptoms: Systemic discoloration (light green leaves, brown spots, yellowing), burning/crispy leaves, one plant with the “claw”

    To this point I'm sure I've made several mistakes. Let temps get too high for a couple weeks (about 85 F, but fixed that about 2 weeks ago. Overwatered a bit for about 2 weeks; not doing that now.

    Plants are not looking good and I'm freaking out. They were looking great about 2 weeks ago. Figured they were getting root bound since they were in 1 gal pots, so I repotted about 1 week ago.

    Today I watered with PH = 7.8 (used PH up) water fortified with ½ strength liquid karma and Cal/Mag. Filled till about 30% runoff and ph was about 5.4! Raised ph of water to 8.6 and ran about 1.5 gallons through each pot and runoff measured about 5.9-6.0. Raised ph again to 9.6 and ran about another 1 gallon through each pot and PH of runoff was 6.3-6.4. Each subsequent watering had ¼ strength liquid karma & ¼ strength cal/mag.

    Please Help!
  2. #2 colafarmer, Sep 18, 2010
    Last edited by a moderator: Sep 18, 2010
    You should not be having ph issues with the root-organics soil. Not sure about Botanicare nutes as long as their organic and not chemical would be alright.
    The low ph is causing a lockout and mg has the symptoms you mention.

    Everything looks good in your grow list.....You did right by flushing your plants now just keep it at ph 6.5-6.8 and look for results...
  3. I've been told that beneficial microbes like mycelium and mycorrhizae can help keep pH balanced in your soil (as well as many other great benefits).
  4. So, now that i've given them a flush with PH adjusted water, will the soil ph stabilize? Or will I likely have to keep watering with PH = 9.6 water?
  5. How are you measuring pH? What type of probe or device? Is it calibrated properly?

    Did you add anything to the soil?

    In general you don't worry too much about the absolute number of the water going it, as long as it gives you the runoff in the right range. But I share your concern that the pH is so low that you will need to pour what will effectively be poison onto your soil in order to get the pH runoff right.

    A flush might do it, report back. But if not, IDK man, maybe a total transplant?
  6. Thanks for the feedback. And yes, I am worried about pouring really high ph adjusted water.

    I am using a digital meter, which was calibrated this week with calibration solution. It was recommended by my hydro store and cost was about $75. I also have compared results of the digital meter to a liquid test (drops in a vial)and another digital meter (pinpoint) I use for my fish tanks. I think the meter is accurate.

    I did not add anything to the soil, but I was thinking to get some dolomite lime and mix it in with new soil and put an extra ~1" soil in each pot on top of the current soil. Not sure if this fix my problem or maybe create a new problem.
  7. sounds like you just had salts built up in soil...would go the dolimite lime route to act as ph water with 6.5 water next time and check run much coco..i use coco and water at if its 50 /50 you might be lookin' at optimal ph between the 2...6.1???hope the ladies come long ago was transplant:smoke:
  8. Honestly not sure what's going on. Till now, I have only watered with straight ph adjusted RO/DI water. No nutes at all. I'm not sure the exact blend of the roots organics soil, so not really sure how much coco they use. It is fortified with lots of organic ferts including bone meals, kelps etc...

    I transplanted them about a week ago. I was in such a rush that I used straight tapwater for their first watering. Today was the first watering since the transplant.

    I am hopeful that they will come around. Not sure if I'm just being positive, or if they actually already look better, just 7 hours after a good flush and watering. Would you expect to see the plants turning around quickly if it was a ph lockout issue?
  9. organic nutes can be tricky....they should show poisitive signs with latest watering...i run my own coco mix that kicks ass and will never go back to soil....would consider this for next easy....check out the coco forum in hydro...good luck bro...its not something your doin' wrong..sometimes the plants just fuck with ya for a you'll be postin they look better tonight:smoke:
  10. Well root-organic soil is premo, so have to discount that it is the soil. Botanicare should be alright but, not sure.
    I think deacon has a good point about salt build up. Don't know your feeding schedule but, would feed 1/2 strength every other watering and take it from there.

    If you still have eratic ph issues your going to have to stabalize the soil. I would use limestone but, dolomite will work. A hydrated lime may work mixed in with water.

    Hopefully you got it all flushed out so, the roots can uptake the nutes now.
  11. Lights off for now. Will check tomorrow and report back. Thanks a lot for all the feedback.
  12. OK, well I'm about 99% sure that the recent flushing has helped. Plants seem more perky. Curling seems to be going away. Leaf color seems to be coming back. Some new growths are looking good. Thanks for all the help.
  13. Look into hydro. It's a lot easier and you don't have these kinds of problems.
  14. Still having major PH issues and could use some help.

    Plants have gotten much much better after the last flush, however, I needed a serious flush again today in order to raise the PH of the runoff. Basically, used 10 gallons of PH = 9.9 water per 3 gallon pot in order to get a runoff PH = 6.4-6.5. Ended up using 3/4 bottle of PH UP for ~40 gallons.

    I am thinking to add some dolomite lime to new soil and adding about 1 inch additional soil. Any thoughts?
  15. I am using botinicare nutes in my hydro grow. I have noticed that when the plant wants a higher concentration of nutes, the ph drops like a rock. The other day I had been using bloom nutes at 800 ppm. The next day the ppm had dropped to <700 (indicating the plant was consuming more nutes than water) and the ph was close to 5.0 when it had been stable at 6 for weeks. I raised the ppm to 950 and the ph increased to 5.5+.
    Just a thought, I don't know if it is the same for soil.

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