RDWC/DWC DO

Discussion in 'Hydroponics' started by Jackson34, Oct 19, 2017.

  1. Jackson34

    Jackson34 Registered

    Others say res water temp is more important than this vital element O2 (DO). I do know that without a continuous supply of enough oxygen within the range of safe o2 concentration, suffocation, sickness and death and decay is predictable and that is a fact whether the aerobes are people, children, babies, plant roots or oxygen loving microbes, dogs or cats. Anaerobes (oxygen haters) like fungi love and thrive in low O2 environments. High O2 environments actually inhibit fungal growth and colonization.

    If dissolved oxygen (DO) in DWC/RDWC reservoir water is insufficient, depending on “how low the DO goes and how long the low DO is present,” that cannabis root cells and aerobic microbial cells can suffocate quickly in the blink of an eye without enough O2 (DO). When the roots die and begin to decay, fungal outbreaks are predictable and happen quickly.

    And the race for the cure is on to kill the feasting fungi… you know the urgent routine with the chemicals and brews when root rot is accidently discovered one morning.

    I have found no one that knows precisely what “low DO” really means. I have also found that the vast majority of growers do not/cannot diagnose a low oxygen problem until they see dead and rotting roots which is always way too late because the damage is already done by then. I have also found that the vast majority of DWC/RDWC do not and have never tested their reservoir water for this vital element (O2, DO) for all kinds of reasons. Yet these same growers will quickly test for many other water quality parameters and adjust water according to test results.

    Maybe someone here knows, maybe not: Not interested in opinions based on water temps and DO chart predictions, been there, done that heard those opinions many times.

    1. What is the optimal DO Concentration “safe range” for DWC/RDWC res water for cannabis in DO PPM in a functional hydroponic life support system?

    2. What is the optimal safe DO Saturation “safe range” for DWC/RDWC res water for cannabis in DO % Saturation in a functional hydroponic life support system?

    Most people only guess and hope their roots don’t suffocate and die. Always checking those roots, waiting, watching, and anticipating dread for months.
    Cheers
     
  2. Weezard

    Weezard Registered+

    And some of us are just pragmatic. :)

    Seriously,I don't need metering for D.O..
    I just overkill with a decent air pump.
    My greenhouse temperature averages 82° F.
    An inexpensive pump will service a 5 gallon DWC bucket quite well if you don't use an air stone.
    The smaller bubbles do not compensate for the backpressure created by an air stone.
    That same pressure also creates more heat in the pump and that will warm your res. and that will allow less D. O..
    Just my experience. Your mileage may vary. :)

    Aloha,
    Wee 'zard
     
  3. Jackson34

    Jackson34 Registered

    The Under Current® system may be the world’s best RDWC hydroponic system on the free market, the web site and images are impressive. The ad copy also reads well too.

    Speaking of DO and the vital importance of "safe" oxygenation, this got my attention:
    The sales point buzz-words, “Hyper-aerabic”… supercharging res water with dissolved oxygen!

    Now that got my attention.

    Sub-Current Culture® (SCC) technology utilizes negative water pressure to recirculate highly oxygenated nutrient solution through the plant’s root zone. This continuous fluid motion supercharges the nutrients with dissolved oxygen, creating hyper-aerobic conditions perfect for explosive plant growth. Constant 24/7 nutrient circulation ensures pH and EC levels are uniform throughout the entire system.

    After contacting this outfit and asking these same 2 questions, their sales staff would not discuss DO other than say, “the Under Current system will supercharge the reservoir water with dissolved oxygen, believe me!”

    What in the world do you think “Hyper-aerabic”… supercharging res water with dissolved oxygen! actually means?

    Sounds important, no?

    I’m a trust and verify, show me type grower and this advertisement does sound interesting nut the staff will not verify what “supercharging res water with dissolved oxygen” means. What that means is so intentionally is no more than the “carrot,” the come-on that stimulates a growers imagination and most important… sales.

    I see, read and hear a lot of shucking and jiving salesman talk here, especially after I took my time to call this company, talk to a salesman and ask these 3 question.

    My questions have not changed and are still the same + 1 new additional question now:

    1. What does “Hyper-aerabic”… supercharging res water with dissolved oxygen” actually mean in terms of DO Concentration and DO Saturation actually tested and confirmed?

    2. What is the optimal DO Concentration “safe range” for DWC/RDWC res water for cannabis in DO PPM in a functional hydroponic life support system?

    3. What is the optimal safe DO Saturation “safe range” for DWC/RDWC res water for cannabis in DO % Saturation in a functional hydroponic life support system?
    Does anyone hear have any factual answers to these questions or no? I’m really not interest in more guessing, this is what by buddy says stuff. I am very interested in facts that are verified in publication. No disrespect to any participating forum member intended.

    Cheers
     
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  4. Weezard

    Weezard Registered+

    Reasonable enough. :)

    As for the marketing hype?
    Marketing hype.

    The facts:

    The amount of dissolved Oxygen is inversely proportional to the water temperature.
    As the water warms, the max D. O. drops.

    Any decent air pump should achieve max D. O. , (100%), for any given temperature.
    This proved true back in the day when I carefully measured everything.
    Claiming anything more than 100% is is 100% bullshit.

    Is it actually possible to "supercharge" your res.?
    Yes.
    But it would require a sealed chamber where you can maintain increased air pressure. :D

    Worth doing?
    No.

    In practical experience, there seems to be little, to no, difference between 100% D.O. and 70%.
    And just like most things. "More than enough, is too much."

    Do not simply "believe me".
    Test it for yourself.

    Aloha,
    Weeze
     
  5. Jackson34

    Jackson34 Registered

    Am I hearing you say that you’re not really too impressed with The Under Current® system internet sales pitch?

    Practical experience has validity, especially if it can be consistently reproduced with a positive end result.

    In a DWC/RDWC sick and dying roots (root rot and fungal infestation) is clear evidence that the growers failed to keep his water quality optimal in his life support system any way you chose paint that picture.

    Speaking of practical experience, have you ever actually tested any DWC/RDWC DO Concentration or DO Saturation in res water of a mature grow 3 months old?

    Or, have you actually tested the water temperature with a thermometer, clicked on an internet DO Chart and predicted your DO from the water temperature on the DO Chart?

    Why do most growers in Hawaii grow cannabis in soil, not hydroponics? Just wondering why...
    Cheers
     
  6. Weezard

    Weezard Registered+

    Ambient temperature. ~82° F.!

    Chilling the res. is expensive enough on the mainland.
    We get gouged for power costs here about 4 X what main-landers pay.

    And this close to the equator we must stretch the daytime with artificial light or our gals will bolt to flower most of the year.
    If forced to flower indoors, the cost becomes prohibitive. Costs more to grow it than to buy it on the street.

    On the big Island soil becomes an expense because we have very little.
    Most of the Island is young lava rock.
    The cost of coco, and good soil is close until you factor in the cost of nutes for the coco.
    Good soil requires only water.
    That's why other folks here choose soil.

    I'm using soil because I'm frugal and lazy. :)

    Aloha,
    Weeze
     
  7. Jackson34

    Jackson34 Registered

    Thanks. Now I understand why hydroponic growing is way too much trouble, a real waste of time and resources in Hawaii. Excellent soil, optimal temperature, less work, less stress, quality products and satisfactory production trumps the cost and aggravation of the hydroponic exercise any way you cut it.

    What is your growing elevation?
    And, how many days from seed sprouting to harvest?
    Cheers...
     
  8. Weezard

    Weezard Registered+



    Yer only right mate.
    I'm at ~ 1000 ft.


    Depends on the seed yah?
    I seldom grow pure Sativa here because they can take 12 weeks to finish.
    And the hybrids get put out when they are ~ half the height I want at harvest.
    However long that takes.

    When I was scrambling, begging trimmings from other growers and accepting gifts to make enough oil for cancer patients. I worried about time to harvest, yields, etc.

    Once I realized that we had been taking way to high a dosage, and now only have 3 patients, the pressure is off and I can get back to growing the fun way.

    Growing for highest quality, and breeding seeds is a joy.
    And it's done for love alone.
    I sell nothing, my excess is donated to folks with limited means.
    So there is no pressure, no rush, no worry. It's an aloha thing.

    Commercial growers are well advised to go hydro. Time is money for them.
    I have hybrid that flower in 49 days. Gifted it's seeds to a commercial grower friend of mine and gave him my DWC/RDWC stuff. It almost doubled his output. Now, people with no other access, (still no open dispensaries on the B. I.) can get what meds they need.

    Aloha,
    Weeze

     
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  9. Rusty Trichome

    Rusty Trichome Registered+

    I run DWC here (near Las Vegas). In the summer, when temps in my reservoir get too warm (over 80ish)... I cut-out beneficials and start using 29% H2O2, instead @1 tsp per gallon. Prevents slime, and the roots thrive. One plant fills a 4x4 trellis under 600w HPS. (Cyco nutrients)
    Guess I should look into another photo host. Any recommendations...?
     
  10. Rusty Trichome

    Rusty Trichome Registered+

    20170301_060906.jpg
    The rest of my photo's are "too large for server to process".
    [​IMG]
     
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