Aeration methods often fail to oxygenate RDWC DWC – Root rot prevention or treatment

Many hobbyist are often confronted with Pythium and other fungal outbreaks. Hobbyist have basically 3 choices when it comes to catching a dose of the Pythium and or other fungal root rot diseases…

Prevent the disease, treat the disease or trash the whole project, disinfect the farm and equipment or buy new equipment that is not contaminated with fungal spores and replant the crop. Then hope you will not catch another dose of the root rot.

If you know of any more options left, please recommend.

Preventing the root rot sounds easy, but treating the disease is really a common thread. I see many hobbyist on pot growing forums that have caught a dose and asking for advice about treating the rot.

Some hobby growers and RDWC “experts” say that “low oxygen” in root zones and nutrient water is the primary cause of root rot. So if all these people are really correct, then it seems very logical to me that IF a grower can or will maintain “safe or optimal oxygenation” the fungal root rot and fungal diseases will be prevented.

About ½ the pot growing hobbyist are not concerned with oxygenation because the DO saturation chart says you will have plenty of dissolved O2 if you keep the res water cold and use some H2O2 or Clorox to kill and keep microbial growth limited. “Low oxygen” is meaningless.

And the root rot marches on.

Many growers believe that there is something to “low oxygen” in the root zone and res solution, but their oxygenation is self-limited to air. They hope that air pumps and bubble stones, waterfalls, fluming, surface agitation and still catch a dose of the root rot.

And the root rot marches on.

2 questions for ½ of hobbyist RDWC/DWC that do believe that “low oxygen” precipitates fungal root rot outbreaks.

*Do you have any idea why all these mechanical aeration devices consistently fail to prevent “low Oxygen” and root rot marches on?

*What DO saturation in the res solution – root zone is “low oxygen?”

Your a . Go away.

YAWN!

let's make this simple for anybody else reading:
@J Henry works for O2grow.com and wants to sell you his overpriced, unnecessary oxygen concentrator.

told you J this wasn't going to be easy once you pissed us off.

Pythium outbreaks are caused by several different reasons. An overpriced air stone will never solve the problem by itself.

blackforest said:

An overpriced air stone will never solve the problem by itself.

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I believe you right, the air stone regardless of the price of the stone is not the solution to this problem and never will be the solution.

This is interesting: What’s your opinion on this piece?

How do I identify and prevent Root Rot?

https://www.icmag.com/modules/Tutorials/PlantTrouble/1289.htm The nutrient DO is unable to supply the root's oxygen demands, leading to prolonged oxygen starvation. Oxygen starvation will result in slow growth, mineral deficiencies, root die-back and reduced yields. Oxygen starvation will stress the plant, leading to an eventual attack by opportunistic pathogens, such as ever-present pythium.

Management strategies [about the cure, not about prevention]

Keeping the crop healthy, vigorous and stress-free is the best "cure" against pythium. Pythium is almost impossible to 100% eradicate from an infected system; this involves starting completely over (with new mothers, containers, equipment, etc). An infected crop can be nursed along, and subsequent crops can still yield, provided the grower takes care to minimize the growth and spread of pythium in the system.

**Starting with a pythium-free system is the best strategy:

Emergency treatment:

1. Hydrogen Peroxide root dunk
   -Remove each plant from system, snip off diseased roots.
   -Dip/swish each plant and container into a strong H2O2 solution, until diseased roots have been removed. Repeat as required.
   
   2. Sterilize equipment
   All equipment should be disinfected (including hoses and pots, etc) with bleach solution or 10% h2o2 solution before plants are reintroduced into the system. Rinse well.
   
   3. Add root rot medication. Add anti-pythium additives, Vitamin B1, and fresh nutrients to a sterilized reservoir at a lower strength, at cooler temps. Reduce light levels. After a week or so, after new roots appear, add some root boost additives.
   

Experimental:

UV Sterilizers. UV can kill waterborne organisms, with a slow exposure to UV light. Research suggests iron can precipitate out of solution. Pythium already attached to surfaces in the rootzone will not flow through the sterilizer and not be killed. Aquarium stores sell them.

1. Continuous drip H2o2. According to Maximum Yield, 100ppm is required to kill pythium in solution. This level also adversely affects small plants. Of course, organics and beneficial bacteria in additives will also be destroyed.
   
   
2. H2o2 should be added to a seperate volume of water and allowed to sit for 20 minutes before adding to the reservoir. The majority of the O2 will be chemically released by the H2o2 by that point. (In high enough concentration, h2o2 will burn off the epeidermis of the roots, exposing it to attack by pathogens and damging fine root hairs).
   
   
3. Slow sand filtration. According to interet literature, SSF can remove up to 99.7% of all bacteria. Aquarium stores sell sand filters.
   
   
4. ** Dissolved Oxygen machines. Artifically injecting water with oxygen may inhibit or kill pytium and other anerobic organisms.
   

J Henry said:

I believe you right, the air stone regardless of the price of the stone is not the solution to this problem and never will be the solution.

This is interesting: What’s your opinion on this piece?

1. ** Dissolved Oxygen machines. Artifically injecting water with oxygen may inhibit or kill pytium and other anerobic organisms.

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My opinion is that this is false and not true.

blackforest said:

My opinion is that this is false and not true.

Click to expand...

Thanks for your opinion.

Many hobbyist say that aerobes probably do need some O2, maybe a little O2, maybe a lot O2.

I have looked and found no scientific research specifically about O2 requirements for RDWC cannabis root zone or nutrient solution. I will keep looking for published material.

Until there’s scientific research on cannabis oxygenation all I see is opinion of hobbyist and water chiller salesmen and aeration equipment salesmen.

Looks like it about a 50-50 split on hobbyist opinion regarding any validation of oxygenation by any means. There are many hobbyist that must deal with and treat the root rot fungi and they keep hoping they will not catch another dose of the rot. If cold water won’t prevent the rot, all hope is lost.

Here’s another oxygenation opinion I found.

How to detect, fix, and prevent root rot in hydroponics http://learnhydro.com/hydroponics/how-to-detect-fix-and-prevent-root-rot-in-hydroponics/
September 1, 2014 by PastLeave a Comment

Note: This site has moved to: http://originalpast420.com

This is an article that I originally wrote on Grass City forums:

How to detect, fix, and prevent root rot in hydroponics

A very common setback in growing is root rot. Luckily, this is very easy to fix/prevent, and can be done so for nearly free, or very inexpensively. This is something you can fix on your own without any fancy products that your local hydroponics store will try to sell you. Knowledge is the key here, not a magical product. If you take 10 minutes to read this, you’ll know how to prevent root rot for the rest of your life.

You can defeat/prevent root rot with one single nutrient, oxygen.

Pythium, AKA root rot, is a living organism (generally considered a parasite) that will thrive in a moist, low oxygen area, where there’s plenty of food. Pythium will feed off the micro/macro nutrients that your plant uses, and the necrotic material of dead roots.

Prevention

Since we know what Pythium need to thrive, it’s as simple as neglecting it, to prevent it. Since Pythium and our plants both need moisture and food to survive, we can’t really deny wither of these requirements or we’ll kill both the Pythium and our plants. The key nutrient here is oxygen. Out plants can’t get enough, and it’s toxic to Pythium.

All you need to do is provide ample amounts of oxygen to the root zone, and root rot will be a thing of the past!

It’s simple in theory, and practice.

Extra oxygen does not prevent root rot in any way by itself. I would argue the contrary that a highly oxygenated/aerated environment would cause the proliferation of bacteria and fungi. If not, Why does it grow on the air stones in an untreated system? High oxygen levels keep the plant's root zone healthy which in itself is helping preventing outbreaks from pythium. Do an experiment. Take 2 5 gal buckets of ro water, put one of your devices in one and nothing in the other. Let us know which system grew more fungi/bacteria after a week.

blackforest said:

Extra oxygen does not prevent root rot in any way by itself

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Just wondering…What do you mean by “extra oxygen?”

blackforest said:

High oxygen levels keep the plant's root zone healthy which in itself is helping preventing outbreaks from pythium.

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What DO saturations do you consider "high oxygen levels?" Do you have a % saturation number in mind or any cannabis research that identifies what "high oxygen levels" actually means.
That's a good idea for a research project, maybe someone has already tried this.Thanks for responding.

J Henry said:

Just wondering…What do you mean by “extra oxygen?”
What DO saturations do you consider "high oxygen levels?" Do you have a % saturation number in mind or any cannabis research that identifies what "high oxygen levels" actually means.
That's a good idea for a research project, maybe someone has already tried this.Thanks for responding.

Click to expand...

Extra oxygen meaning aerated water vs. non aerated water

There is no cannabis research that will give you empirical evidence due to Cannabis being a schedule I drug preventing any peer reviewed research. At the same time I would say high oxygen levels means optimal DO for nutrient uptake, whatever that number is. Optimal DO appears achievable with mid 60's water temp and some simple air stones, and sometimes no air stones at all. Read some of the topics here from current culture's website. They have some good info: http://cch2o.com/rdwc-hydroponics-growers-guide/

blackforest said:

At the same time I would say high oxygen levels means optimal DO for nutrient uptake, whatever that number is.

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Have you ever actually tested DO % saturation in your nutrient water? Or just go by a DO sat chart based on air and water temperature?

blackforest said:

They have some good info: http://cch2o.com/rdwc-hydroponics-growers-guide/

Click to expand...

All I see here is company sales literature pushing cold water and water chillers. Nothing here about what “Low DO sat” is or what “high DO sat” is. Not much to go on here in the sales lit.

MAINTAINING OPTIMUM NUTRIENT TRMPERATURES

1. Although the system can operate with nutrient temperatures exceeding 68 degrees F, maintaining a cooler water temperature between 65-68 degrees F is ideal.

2. *At these cooler temperatures you will get the highest levels of dissolved oxygen without slowing plants metabolism.

3. After attaching your water chiller in one of the several ways listed on Page 7 of the Assembly Instructions, adjust the thermostat to the desired temperature.

Thanks for the sales info.

J Henry said:

Have you ever actually tested DO % saturation in your nutrient water? Or just go by a DO sat chart based on air and water temperature?


All I see here is company sales literature pushing cold water and water chillers. Nothing here about what “Low DO sat” is or what “high DO sat” is. Not much to go on here in the sales lit.

MAINTAINING OPTIMUM NUTRIENT TRMPERATURES

1. Although the system can operate with nutrient temperatures exceeding 68 degrees F, maintaining a cooler water temperature between 65-68 degrees F is ideal.

2. *At these cooler temperatures you will get the highest levels of dissolved oxygen without slowing plants metabolism.

3. After attaching your water chiller in one of the several ways listed on Page 7 of the Assembly Instructions, adjust the thermostat to the desired temperature.

Thanks for the sales info.

Click to expand...

You should probably just stop posting in these forums. You are redefining the term Troll.

Another opinion about oxygen

Nutrients for hydroponic systems

Dissolved oxygen DO http://www.homehydrosystems.com/nutrients/oxygen_page.html

A hydroponic nutrient solution is not just a mix of fertilizer salts and water. One of the most important of these is dissolved oxygen (DO), which is vital for the health and strength of the root system as well as being necessary for nutrient uptake. Plants breath just like all organisms via respiration.
Oxygen is an essential plant nutrient – plant root systems require oxygen for aerobic respiration, an essential plant process that releases energy for root growth and nutrient uptake. In many water-based hydroponic systems,the oxygen supplied for plant root uptake is provided mostly as dissolved oxygen (DO) in the nutrient solution as well as a zone of aeration provided by a gap from the surface to the reservoir water level.

Oxygen requirements for plants in flower tend to be more demanding in comparison to vegetative states. This is due to the size of the root system, temperature, and nutrient uptake rates, not the specific stage of growth.

Injury from low (or no) oxygen in the root zone can take several forms and these will differ in severity between plant types. Often the first sign of inadequate oxygen supply to the roots is wilting of the plant under warm conditions and high light levels. Insufficient oxygen reduces the permeability of the roots to water and there will be an accumulation of toxins, so that both water and minerals are not absorbed in sufficient amounts to support plant growth.

While it is possible to measure the levels of dissolved oxygen in a hydroponic nutrient solution, it is not carried out as often as EC/ppm or pH monitoring due to the cost of accurate DO meters.

[Now here is the classic pivot I see so often, “the switch” from the word oxygen to the word air (aeration) without skipping a beat. Most people know that air is not oxygen]

However, if an effective method of aeration is continually being used, and solution temperatures are not reaching excessively high levels, then good levels of oxygenation can be achieved without trouble.

Most growers are familiar with the need to have some sort of aeration in their nutrient solution due to waters high surface tension – whether they are in a recirculating water-based or media-based system.

[DO meters are too expensive for most hobbyist, so the pivot to the DO chart is substituted now and DO is assumed based on water temperature estimated with air as source gas]

However, the effect of temperature of the solution on the DO levels and on root respiration rates also needs to be taken into account. As the temperature of your nutrient solution increases, the ability of that solution to hold DO decreases. For example, the oxygen content of a fully aerated solution at 50 F (10 C) is about 13 ppm, but as the solution warms up to 68 F (20 C) the ability of the liquid to ‘hold’ oxygen drops to 9-10 ppm.

By the time the solution has reached 86 F (30 C) it is only 7 ppm. While this may not seem like a huge drop in the amount of DO, we have to remember that as the temperature of the root system warms, the rate of respiration of the root tissue also increases and more oxygen is required by the plant. For example, the respiration rate of the roots will double for each 10 C rise in temperature up to 86 F (30 C).

***So the situation can develop where the solution temperature increases from 68-86 F (20-30 C) during the day, with a mature crop, then the requirement for oxygen will double while the oxygen carrying capacity of the solution will drop by 25%. This means that the DO in solution will be much more rapidly depleted and then plants can suffer from oxygen starvation (root rot) for a period of time.
Perhaps one of the commonest problems in hydropnic systems is the Pythium pathogen. What many growers do not realize is that Pythium, being an “opportunist” fungi, often takes advantage of plants which have been stressed by a combination of high temperatures and oxygen starvation in the root zone.

Pythium is usually described as a “secondary infection” meaning that the Pythium spores that are actually common in just about all hydroponic systems, don't actually attack the plant until it has been damaged in some way.

*** Pythium is everywhere, so the best defense is a healthy plant.

What about the hydrogen byproduct in a sealed grow room environment? These are similar to the emitters used in hydrogen conversions for cars. I know the technology, I've played with them. A half gallon of water produces enough hydrogen to run a V8 engine, or enough to make a small bomb, I can't imagine how much hydrogen you would produce out of a 10 gal res. .or larger. Pure o2 and hydrogen in a sealed grow room. Your going to kill someone, hopefully yourself before someone else.