Questions about PH levels before and after watering (runoff)

Discussion in 'Growing Marijuana Indoors' started by shagwells, Jan 11, 2013.

  1. Hey GC,

    Please point me to the right direction on this one. My filtered brita water seems to have a PH of 7.2 so I PH down to about 6.5 on the water and then water the plant.

    Then I measure the runoff of this brand new Roots Organic Soil I just watered with and it comes out like 4.

    Naturally it tells me to just water the brita water at 7.2 PH and see if it balances it out, but it's still reading around 4's (PH).

    So I have 2 questions:

    1) The PH reading on the runoff water is the most important value, right? Meaning it doesn't matter what PH water I put in, because it only matters what comes out right?

    2) What do I do then? Ph UP to like 8 and water it and see what it comes out at?

    I wanted to clarify this first before doing anything actually.
    Stats: 400w HPS, Roots Organic, Fox farm trio line, Only PH meter is the dye drip tester (The kit that has that + PHup/down)
  2. Dolomite lime - sprinkle some on top (next time mix it before planting) - Will bring you ph and buffer it around 6.7 - 7
  3. I would add pro-mix to your soil.I just went through a nightmare with adding lime.I added 2 much,and all my shit almost died.And what didnt was ruined anyway.

    Adding lime can take awhile before it actually works for you.

    Pro-mix is Pre-limed,and ready to go.It should help buffer your PH if you do like a 50/50 mix of pro mix,and what you have now.
  4. /bump - hasn't been answered yet.
  5. Ive never measured my run off. Ive also never had ph issues that wernt fixed by me correctly phing my next watering... so idk

  6. Have any pics of what that over-liming looks like? Really curious about it, so I'd greatly appreciate it. It's the one thing I've feared doing and might be causing a problem on one of my babys.
  7. Let me ask you this - are you growing in soil?

  8. Of course man.

    I measure the PH of the runoff water on my roots organic soil and the PH comes out to be like 4. So naturally it tells me there is something in there that is really low in PH and I'm not sure if my plants get nutrients from it.

    So you guys don't measure the PH off the runoff water?

  9. Over limimg causes Multipul lockouts causing everyhting to yellow up with brown spots/patches.I also got a lot of purple stem.

    mag,iron,zinc,and phosphorus are quite noticable deficiancies..

    Looks a lot like really really bad nute burn in some cases.

    I treated for all of these issues,and finally remember how I had added lime to the soil months before.
  10. #11 StayLowGrows, Jan 12, 2013
    Last edited by a moderator: Jan 12, 2013
    Wrong topic. If it becomes relevant or questioned, I'll put this post back up.
  11. #12 shagwells, Jan 12, 2013
    Last edited by a moderator: Jan 12, 2013
    This is why I got into measuring PH of my water and what not. My stems are purple too but healthy. But a lot of the times they show a calcium and on rare cares magnesium deficiency. So I tried Cal Mag. It didn't help...

    So at this point, it really narrows it down by saying the nutes are gettings locked out due to PH issues because certain nutes are only available on certain range of PH's.

    Then I decided to get new soil from Fox Farm Ocean Forest to Roots Organic. On the FFoF, the Brita filtered water I adjust the PH so that it's at 6.5ish or slightly lower and then water it (all nutes are available in that range). Then I measure the runoff and it's about the same when it comes out. I also adjust the PH on my brita water that I put Big Bloom and Grow Big/Tiger Bloom into and again, the runoff water is about the same.

    But when I changed it to Roots, Everything comes out like 2-3 ph lower. I'm thinking Roots PH'ed it down on purpose so that it doesn't result in other people's plants getting nute burned?

    Either way, I'm thinking the PH I get from the runoff is more important than the PH of the water you put in (or equally important); because it's the soil that takes the benefit either way and it shouldn't come out all off on the PH after you mix water+soil together.

    Can someone correct me on this if I'm wrong? This is what I'm trying to find out. Is the PH level on the runoff water equally as important? Should the water you put in be adjusted to reflect the ph outcome of the runoff water? Meaning should I adjust my PH of the water that I put in so that it balances out @ the runoff.

    Below is a Nutrient Availability Chart.

    Attached Files:

  12. Well fuck me! My last post was meant elsewhere. Sorry man......I feel stupid as hell cause you followed with 6 paragraphs too....geez
  13. It's ok, but the reason you get purple stems is because your PH is off.
  14. #15 StayLowGrows, Jan 12, 2013
    Last edited by a moderator: Jan 12, 2013
    Well, I just got stoned. Refreshed the page. Still can't believe I did that.

    I apologize to everyone about that. I haven't got high today until now. haha

    Company just came over, so I'll get back in an hour.
    What a shame you never got an answer on this.... What ended up happening to the plants?

    This is relevant and useful:

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