how to check runoff correctly?

Discussion in 'Growing Marijuana Indoors' started by Didly, Jan 2, 2011.

  1. Hey GC,
    Im just curious if there is a proper way to checking the ph of my soil....
    I have caught all of the run off.... i have caught the last bit of run off... everytime the ph is the same as the water i put in... i put in 6.8 water and the ph was 6.8...
    Another time i watered w. 7.3 water and the runoff was 7.3..
    What am i doing wrong
     
  2. there are lots of different ph measuring devices, some are more efficient than others. any reason you watered with ph 7.3? it's a bit high, if you are in dirt than try to get it around 6.5....
     
  3. Well it was an accident.. i have a milwaukee ph600.
    The ph of the run off was the same as the water i put in.
    Why is this?
     
  4. Thats fine that its the same as going in. It depends if you have any nutes built up in the soil, or any other deposits.


    What medium are you using to grow with?
     
  5. #5 AYOOOOOO, Jan 2, 2011
    Last edited: Jan 2, 2011
    I have the same ph meter, what I do is make a gallon of ph balanced water (ph=7) and then pour the water while having something to catch the run off from the bottom. The key is to check the ph of the water that first starts to come out , this will give you your true ph.

    Edit: Make sure you're checking the water that flows out of the bottom of your pot, NOT the water that flows over the top.
     
  6. How I do it is this:

    Water well to run off and the medium is fully saturated. Toss all the run off water.

    Let the plant sit 1/2 hr to 1 hr or so.

    Add enough water to get enough new run off to measure. Measure this run off. The water, being in contact with the soil for a time, gives a a more accurate reading.

    Wet
     
  7. #7 AYOOOOOO, Jan 2, 2011
    Last edited: Jan 2, 2011
    Correct me if I'm wrong, but won't you just end up with the same problem as the OP if you do it this way? Leave it saturated that is.

    I'm pretty sure you want the first water drops that come out for an accurate reading.
     
  8. #8 wetdog, Jan 2, 2011
    Last edited by a moderator: Jan 2, 2011
    You aren't LEAVING it saturated, you are just watering again 1/2-1hr later and checking that runoff. You don't change your normal watering or anything.

    It's a lazy way of mixing some soil up with distilled water, letting it sit and then measuring the pH.

    Of course, you check the pH of the water used to water. Let it react with the soil for a length of time, then add some more of the same water and check the pH of that runoff.

    To me, this seems to give the most accurate reading when you need to get something dialed in as the OP does.

    HOWEVER >>>> Most of the time, I do it just like you and measure the first run off. I grow in a well limed organic mix with a healthy micro herd and seldom need to check the pH. If the first run off is 6.5-6.8, I don't look further.

    Wet
     
  9. Gotcha

    I wasn't trying to put you on blast or anything, just trying to comprehend why.
     

  10. How fast is the run off coming out? Like, is it coming out as soon as you water, or 20-30 seconds later? What I mean is, is the mix absorbing it?

    Usually, there is SOME change from the water going in and the water coming out.

    Wet
     

  11. LOL We're good, just trying to get the OP squared away.

    Wet
     
  12. Thanks everyone for your help. Well i am growing in soil.
    Ednas best orhanic potting soil earthworn castins and perlite...
    Um yeah i was gonna ask maybe its becaise im in solo cups and the run off is almost instany.. i was thinking maybe i put tomany drain holes.
    I will try watering it a second time to see if it makes a difference.
    Also. When trying to catch the 1st runoff due i wanna not get all the water just the 1st couple seconds of it?. If it matters i have only gave them guano once... and when i checked it this time i fed them FF growbig and cal mag.. i wasnt able to find dolomite lime.. if i was to aquire it now how would i go about mixing it w. My soil?
     

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