DWC Root Slime Cure aka How to Breed Beneficial Microbes

Discussion in 'DWC/ Bubbleponics' started by Heisenberg, Aug 26, 2010.

    J Henry

    J Henry Active Member

    TWS, playing around and manipulating dissolved gas saturation, supersaturation and concentration using Chemistry Laws is fun and often profitable too.

    Henry, a chemist of long ago, had an idea like supersaturating a can of Dr. Pepper with gas to make it effervescent when opened. How much gas is really possible to dissolve into water and force into solution? What are the limitations and so on? His hypothesis, over time proved always true and correct. His idea eventually solidified and a Chemistry Gas Law was born. A law as true, stable and reliable as Newton’s Laws of Gravity.

    Here’s how the basic chemistry of dissolved gas solubility works (manipulating gas tension in the water) - Henry’s Gas Law applied:

    The gas tension (individual gas pressure) is what makes gas molecules move from point A to point B… drives the gas molecule from the gas phase into solution or dissolves the gas into the water. The greater the tension the more gas dissolved into the water.

    Conditions: Air (20% oxygen/80% nitrogen), fresh water, stable water temperature, 0.0 solute, sea level barometric pressure (760 mm/hg). If you know the % of the gas , and we do, know the barometric pressure and the solute concentrate, here’s the math.

    Barometric pressure X % of gas = gas tension or pressure at sea level

    1. Air contains only 2 major gases 20% Oxygen and 80% Nitrogen
    760 mm X 0.2 = 152 mm/hg gas tension

    1. Air contains 80% Nitrogen
    760 mm/hg X 0.8 = 608 mm/hg gas tension

    2. Pure 100% Oxygen O2 the element is only 1 gas

    760 mm/hg X 1.0 = 760 mm/hg gas tension

    400% more O2 gas dissolves in water in normal environmental conditions using 100% pure O2 vs. using air (aeration) that contains only 20% oxygen in the mixture of gases.

    Tremendous amounts of Nitrogen dissolve into water when air is dissolved – 608 mm/hg nitrogen (that’s aeration). But, dissolving a lot of Nitrogen gas in res water is really not the point of oxygenation if and when minimal safe “oxygenation is the whole point.”

    When manipulating dissolved oxygen is the point, the difference between using air and using O2 becomes clear, at least it does to me. When dissolving air into water, the % O2 gas in air is the limiting factor. The DO is controlled by water temperature; dissolved solute concentrations and barometric pressure, but the limiting factor of dissolved oxygen is always the % of oxygen gas being dissolved.

    Heisenberg Well-Known Member

    It's been years since I wrote that, but I do believe I clarified at some point that we can never hope to raise DO levels to those able to satisfy the roots. The aim is really to facilitate a favorable environment for beneficial microbes. The heuristic I gave of "1wt per gallon" also seems a little arbitrary now, but I suppose it works good enough as a rule of thumb.

    I no longer use the tea myself. I actually saw a hint of slime not long ago, the first in years, and I did not bother to check my water temp or throw in another airstone. My plants are quite healthy and I knew a few more bubbles in the brew wasn't going to make the problem go away. I just added a splash of Kangaroots and two days later things were back to normal. I don't know why it showed up or what triggered it, and I no longer care. I used to see the slime as a sign of a serious flaw in methodology, but now I know it's just a bump in the road. Mother nature likes to wiggle her fingers once in a while.

    I think today I would give a different sort of advice to those fighting slime. It would be the same basic stuff, but there is no need to be so meticulous about things. Make sure your res is cool, has bubbles, and no light leaks. When making tea, you can just use dash of microbe powder, a chunk of EWC and a little molasses. No need to get the measurements just right. No need to order multiple products to try and get the most diverse mix. No need to overly scrutinize your DO levels or water temps. Brew it up for 48hrs and dump some in the res.

    The one common factor that showed up the most to those with a continuous slime problem was some sort of organic additive.
    jijiandfarmgang and jimmy311 like this.
    J Henry

    J Henry Active Member

    Hello Heisenberg,

    I did not know that you have abandoned the tea. OK, let’s move on from aerating tea with an air pumps to insuring long term continuous safe oxygenation for dual eco systems in DWC with oxygen, the gas.

    Yes, I did see that you have clarified that we can never hope to raise DO levels to those able to satisfy the roots. Are you absolutely sure about this?

    “Good enough” is OK for the average DWC grower as you mentioned. This is for growers where “good enough” is not even close to the real high-tech growers applying cutting-edge growing methods to produce the highest quality product.

    Surely we cannot simply dismiss that additional oxygen is surely necessary to satisfy the biological demand of the total biomass of aerobic micro-organisms necessary for plant health so easily... that is IF we really want build a thriving healthy DWC system that will produce the highest quality product.

    Maintaining 2 healthy eco systems in recirculating DWC requires a lot of oxygen, if microbe health and reproduction is an issue. I seriously doubt that “1 wt. per gallon” works at all as a rule of thumb if “the aim is really to facilitate a favorable [oxygenated] environment for beneficial microbes.” No disrespect intended?

    The collective oxygen demand for 2 symbiotic eco systems working in harmony throughout the complete growing period (months) should be a very important consideration since a continuous supply of oxygen of high concentration is such a vital nutrient. Hypoxia kills in hours, starvation kills in days.

    Two eco systems require much more oxygen than just the minimum safe amount of oxygen requires to sustain a healthy plant eco system and root zone. For all the plants and microbes to remain healthy and thrive, the grower must deliver and dissolve sufficient volumes of highly concentrated oxygen sufficient for both eco system 24/7, 7 days a week continuously for many months. It seems logical to me that any responsible grower would be keenly aware of the oxygen demands of his crop and microbes and provide a continuous supply/volume of oxygen of sufficient concentration for all the plants and all the microbes continuously throughout the months of the growing season.

    About wasting expensive nutrients.

    Nutrients usually metabolize very well in healthy oxygenated plant and microbe cells. When mitochondria are deprived of oxygen for any reason (disease, hypoxic environment, low oxygen environments, etc.), cellular metabolism malfunctions, nutrients are not metabolized efficiently and wasted. Plant and microbe hypoxia, even sustained low DO saturations do guarantee the cellular fire to only smolder at best, the cellular fire will burn efficiently and bright.

    Imagine for a moment, if you really want the absolute best oxygenation for your DWC plants and microbes. What DO Saturation is ideal?

    In your opinion, what do you think is the best continuous DO possible for your DWC? This is DO only, disregarding standard water temperature 65-68 F so often recommended so you can to obtain the greatest DO in cold water, solute concentration and barometric pressure:

    Warmer water insures higher metabolism equals faster plant and microbe growth equals more microbe reproduction equals more product to market equals higher yearly profits.

    I invite you to think out-of-the-box for a moment, use your imagination. About DO

    If, in your DWC, you could sustain any DO continuously 24/7 throughout the total growing period (insure plenty of oxygen for the plant, the roots and all the microbes collectively… what ideal DO would you choose?

    Low-oxygen (sub DO saturation with air, air pumps or any mechanical aeration)

    DO saturation (!00% DO saturation at any water temp)

    DO Supersaturation (>100% DO Saturation at any water temp)

    Thanks Heisenberg for responding so quickly,

    J Henry

    J Henry Active Member


    Please recommendation a Plant Physiologist that teaches at a University or College in the US.

    University or College affiliation, Professors name, email address, phone number.



    IamLordeYaYaYa Member


    Love using the tea in dwc(when I feel i have the time). quick questions though :
    1. Can I use the brew in hydro and soil(less)?
    2. since I read pumps can kill the bacteria: Can you use the tea in a pressurized mister?
    3. Does more molasses (like a LOT dissolved first in boiling water) make the brew take longer (past 48h?)

    IamLordeYaYaYa Member

    Used it in my perlite/Peat seedlings and it seems to be going well.

    Something interesting though: I found the morning after I feeding: a weird yellow ball on the top of the soil. Popped it, it was kind of like an advil liquidgel tablet. Im pretty sure it was a little bit of the tea solidiying. Wish I grabbed a pic before I popped it.
    J Henry

    J Henry Active Member

    Hay Ya-Ya, when the next one of those yellow balls surfaces again, please take a pic and post it. I may I have seen this before. Just in case it is a fruiting fungi, a fungicide may be indicated or you might carefully excise it including a moderate area around the roots where foots are not visible. If fit is a fruiting fungi, popping it could spread it like stomping a "puff-ball" in the woods. Or like the like a inexperienced surgeon that cuts into a cancerous tumor thus facilitating the tumor cells to metastasis.

    IamLordeYaYaYa Member

    Thanks, I'll make sure to take a picture and keep an eye out if it happens again, but I am pretty sure it wasn't fungal (at least macroscopically so, as there are mycos in the tea). the ball wasn't attached to anything, just a complete, perfect sphere of crystalized liquid. It seemed like a bead of the tea or something, it was just strange that it solidified. Im thinking maybe the molasses wasn't completely dissolved or something. Also my temps are 90F right now, so theres that.

    Update: the 90F temps are the AIR temps in my veg (soil) cab. The air is probably a touch under 90F, since the sensor is on the tray which is on a heating pad.
    Last edited: Feb 7, 2016
    J Henry

    J Henry Active Member

    Do your plants grow better at higher water temps 80F - 90F and the ambient air temp is stable at 70F with circulating air?

    IamLordeYaYaYa Member

    Air temps are high, water temps are low. The higher temp room doesnt have any hydro atm, at least until air circulation is better.

    The Air temps are pretty manageable inside both rooms, but the air is pretty warm diriectly above the lid to the hydro system since I keep my lights low.

    So far everything is growing fine, but I only have 1 rez I gotta worry about cooling. She's growing voraciously, however.

    drakule New Member

    Question for Heisenberg .... i currently have 4 sprouts running in RDWC .. previously i had a bout of slime and went about nuking it with pool shock after i failed on last crop .. i rinsed / put in H2o2 rinsed again and dialed in nutes ( GH 3 part ) + Hygrozyme ( Advice from local grow store that it eats up any returning slime ) and put the 4 sprouts in there .. yesterday i noticed a couple of small bits of mucus flapping around in the supply reservoir water in buckets with plants looked fine .. i decided to drain and put in fresh RO water with 2.5 ML of kangaroots per gallon ( as on bottle ) + 20 ml Hydroguard , an hour later the water is really cloudy with each bucket + reservoir swimming with dozens of half cornflake size white mucus .. is this normal or should i drain again and take a different approach to this ? .. Many thanks in advance .. System is a 5 Bucket RDWC 5 x 5 gallon under 700 w led + 400 w HPS .. external 300 gph aquarium filter + 1/10 hp chiller with water temps at a constant 68 !
    Edit : just checked two hours later .. cloudiness has decipated somewhat .. floating particles of mucus are still hovering around , got the largest airstones possible in those buckets so hoping to stem the tide here :)
    Last edited: Feb 8, 2016

    drakule New Member

    Further edit: Mucus seems to have cleared up in 48 hours things are looking better .. Brewing compost tea with Kangaroots / ocean forest / molasses and going to add that to a fresh batch of RO water tomorrow

    GrowTeam Active Member

    or you could just use 1ml/gallon of clorox bleach. You will never run out of the stuff. Use it every few days.

    Punchedinthejunk New Member

    I have tried to read and take in all the info in this thread (Which is impossible), But don't H2O2 and bleach make a bad combo? Sorry, I'm a TOTAL noob. Just trying my first round of hydro and trying to kill my root rot

    fishdeth Well-Known Member

    Forget the bleach, forget the hydrogen peroxide... brew the tea as closely to the recipe supplied in this thread, keep your res / soup temps under 70F and GROW ON !
    It's tried
    It's true
    It WORKS
    And you will have some real happy plants !!!
    J Henry

    J Henry Active Member

    what does this particular tea really do, why all the sugar in it?

    Hawzzy Member

    Hello everyone...great info. Figured id share my success story.

    I was running two buckets plus a control, dwc, one with two plants one with four. THE SLIME
    took over and I lost the four plant bucket very quickly....then I found this thread.

    I removed the two remaining plants...drained and sterilized the system then filled with PHd water. Those two plants were bathed In a mild bleach solution while I cleaned everything.

    Meanwhile I had already been brewing my tea fr 48 hours. My recipe is as follows...
    Handful of Ancient Forest in a sock.
    1 gallon water
    1 to 2 tsp organic mollasses
    1/4 tsp subculture b
    I start with a cup of hot water to mix with the mollasses then add it to the bucket and bubble for an hour or two to remove the chlorine. (I always have a couple buckets sitting out at anytime)
    I add an airline with a splitter and two air stones....one in the sock and one underneath.
    Bubble for 48 hours stirring occasionally.
    20160128_223748.jpg 20160222_132035.jpg
    Before tea...............after tea
    Just 2 to 3 weeks between.

    I have all the confidence in the world that using the tea as prevention from the beginning will aid in much success and healthy plants in the future
    Last edited: Feb 22, 2016
    Heisenberg likes this.
    J Henry

    J Henry Active Member

    What were the conditions that developed that caused the slime opportunist to thrive in your DWC?

    GrowTeam Active Member

    Yea never mix h202 and bleach.

    Hawzzy Member

    [Qbelieve"J Henry, post: 12348826, member: 922955"]What were the conditions that developed that caused the slime opportunist to thrive in your DWC?[/QUOTE]

    When I started my two tub rdwc...i started with a few rooted clones and two clones that I stripped the soil off, rinsed, and placed in one of the tubs. They had a decent root structure BUT were obviously stressed from the transplant.

    I double checked for light leaks...my temps were actually in the low 60's. My first research suggested bleach and or H2O2 baths and stripping the dark dead roots. It was a waste of time and set me back weeks.....

    So I think I may have introduced the slime or algae, probably from the soil started clones.

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