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DWC PH issues: Ph dropping like a rock - Please help

Discussion in 'DWC/ Bubbleponics' started by John1961, Nov 5, 2017.

  1.  
    John1961

    John1961 Active Member

    @firsttimeARE - Can you expand on what you mean by "sterile res"? Is that the same thing that @rkymtnman is suggesting, running with plain RO water as a 24-hour flush?
     
  2.  
    firsttimeARE

    firsttimeARE Well-Known Member

    Nae using H2O2 horticulture grade 17% or better or HTH pool shock
     
    HydroRed likes this.
  3.  
    John1961

    John1961 Active Member

    @rkymtnman & @firsttimeARE - Your thoughts please.

    Assuming I proceed with a RO flush tomorrow (two reservoir changes x 12 hours each), should I consider using some H2O2 during the flush to address a possible bacterial issue (if there is one)? I mean, is there a potential for damaging or hurting anything if I do a H2O2 flush without a bacterial problem present? If I use H2O2, how much should I use for 5 gallons of water?

    Or should I just use plain RO water and see what happens during the flush?
     
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  4.  
    rkymtnman

    rkymtnman Well-Known Member

    i'm personally not a fan of peroxide. it does work but it's harsh.

    if it were me, do one thing at a time.
    24hr RO flush first. see what happens.

    if that does nothing, let's try a sterile res for a week and see what that does with your normal nute routine. call that hydro shop and see what they have as far as a chlorine root zone additive. dutchmaster zone, UC roots are 2 off the top of my head. i use HTH pool shock but you need a fairly accurate scale to do it. if you have one, i can give you the mix instructions
     
    HydroRed likes this.
  5.  
    firsttimeARE

    firsttimeARE Well-Known Member

    17% i was using 3ml roughly a gallon.

    Its fine just dont pour it directly on the plant. And dont,get it on your skin. Burns a bit and will temporarily turn the skin white. Ask,me how,i know? Lol.

    Havent used it in like 5-6 years though. I guess im just lucky cause I dont use anything. Sterile or beneficial.

    Im on day 30 of my RDWC res and roots still pearly white. I probably will keep the res throughout all of flower.
     
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  6.  
    rkymtnman

    rkymtnman Well-Known Member

    that was that summer of 2014 where everybody called you an albino??? lol.
     
  7.  
    John1961

    John1961 Active Member

    Well, it's been 8 hours since I added 4ml of PH-Up to the reservoir to get the PH back up to 6.3 this morning.

    In the past eight hours, PH has dropped to 5 2. I just added another 3ml of PH-Up to the reservoir and will give it an hour to bubble before checking PH again.

    On the plus side, she is drinking plenty of water. I had to add about a half gallon to the reservoir.
     
  8.  
    rkymtnman

    rkymtnman Well-Known Member

    that's a good sign.

    is your ppm still barely dropping?
     
  9.  
    John1961

    John1961 Active Member

    PPMs went up from 650 this morning to 690 at present. EC remains unchanged at 1.4.
     
  10.  
    firsttimeARE

    firsttimeARE Well-Known Member

    Kick it back down to 550ppm

    Thats a big rise for one day.

    Bring your pH up with water and dilute it at the same time
     
  11.  
    John1961

    John1961 Active Member

    Thanks, @firsttimeARE . Bear in mind this reservoir water cycle used tap water with a PPM of 180. But I'm guessing after tomorrow's RO-water flush, best case scenario is I'd start with low nutrients anyway.

    I just took tonight's readings right before lights out. I'll be back in the morning with what happened overnight.
     
  12.  
    John1961

    John1961 Active Member

    Good morning, folks.

    Last night's PH drop was not as severe as I was expecting. Here are my morning numbers:
    • PH: Went DOWN from 6.3 to 6.1
    • PPM: Went DOWN from 690 to 660
    • EC: Went DOWN from 1.4 to 1.3
    • Water Level: Went DOWN ~1 pint
    I went ahead and pumped out the reservoir and pumped in fresh RO water (nothing added). I'm gonna give the reservoir an hour or so to bubble and will then make note of my PH, PPM, and EC. I'll do the same this evening when I do another res change about 11 hours from now.

    I've attached a few pics. I really think the reservoir is free of any bacteria. The air stones, tubes, and sides of the tub are as clean as the day I started this grow back in August.

    7f_11a.jpg 7f_11b.jpg 7f_11c.jpg
     
    Last edited: Nov 15, 2017
  13.  
    rkymtnman

    rkymtnman Well-Known Member

    do you run your intake/exhaust 24/7 or just when lights are on?

    and remind us, the plant is in bloom now, correct? for how long?
     
  14.  
    John1961

    John1961 Active Member

    Yes, the intake fan and exhaust fan run 24/7.

    It has been 11 days since I switched to flower.
     
  15.  
    rkymtnman

    rkymtnman Well-Known Member

    any flowers starting to form? hard to tell in that one pic
     
  16.  
    John1961

    John1961 Active Member

    Looking close at the tops, just a few pistils are starting to form. I'm also seeing a few pistils shooting out from some of the lower nodes.

    7f_11d.jpg 7f_11e.jpg 7f_11f.jpg
     
  17.  
    70's natureboy

    70's natureboy Well-Known Member

    Well, that's interesting, GH is pretty ph balanced in my experience. I also use GH in DWC and have stable PH with tap water. Sometimes i will add 1ml/gal of ph down if I'm feeding light. I usually use 5-7 ml/gal of micro and 10-15 ml/gal of bloom. a light Lucas Formula, to get me between 5-700 ppms. That chart back a couple pages said if your ph is going down your nutes are too strong.

    I don't trust ph meters either. Will your meter give you a repeatable reading? Maybe something up with the tap water. Is it from a well or municipal? I guess I'm stumped so best of luck.
     
  18.  
    John1961

    John1961 Active Member

    Well, here are tonight's numbers after 11 hours of bubbling away with straight RO water:
    • PH: Went DOWN to 6.3 from a reading of 6.6 this morning.
    • PPM / EC: 0 (zero)
    • Water Level: She drank a good half-gallon of water in the past 11 hours alone!
    A couple of the very oldest and lowest leaves have begun curling / shriveling, suggesting that she is very hungry!

    So after tonight's straight-RO flush, what should my plan be for tomorrow as far as nutrients go? I'll be using RO water from here on out. Should I shoot for a starting PPM of say 300? More? Less?

    Regarding the small drop in PH. In comparison to the daily drops I was seeing when the water had nutrients in it, should I consider a different brand of nutrients? I know GH is supposed to be at the top of the game, but maybe it's just not working for my particular environment?
     
  19.  
    rkymtnman

    rkymtnman Well-Known Member

    i was expecting that. very good.
    heres' what i'd do:
    fill up with normal amount of RO
    use 3mL micro, 6mL bloom (no grow) per gallon RO. use max dose hydroguard per gallon.

    she should eat like crazy. keep us posted. if she does, we can bump up your ppm really easy.
     
    HydroRed likes this.
  20.  
    John1961

    John1961 Active Member

    Good morning, folks. Morning numbers:

    PH: Remained stable overnight at 6.6.
    PPM / EC: 0 (zero)
    Water level: Went down less than a pint.
     

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