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How do you oxigenate your reservoir?

Dr.Dutch

Well-known member
Using air pumps and bubblers to oxygenate a reservoir for the roots/plants is completely unnecessary and bro-science when growing in coco substrate. Coco coir naturally contains a lot of air, providing ample oxygen to the roots. This practice is only relevant in water-based systems like Deep Water Culture (DWC), where maintaining dissolved oxygen levels in the water is crucial.
Water circulation in your reservoir for coco is only necessary to prevent the water from becoming anaerobic.

PS:
And please leave the H2O2 out of your nutrient solution. At that concentration, it does absolutely nothing against fungi or bacteria. Instead, it reacts with the chelates, potentially causing some micronutrients to precipitate out, and it disappears from the nutrient solution in a very short time. See also

From these choices, both hypochlorite and hydrogen peroxide have poor disinfection performance at the concentrations tolerated by plants and are hard to maintain at the desired concentrations through an entire crop cycle without ill effects


Healthy roots minimally leach nutrients into solution [101]. In our experience, increased turbidity usually indicates unhealthy roots with carbohydrate leakage. We have found that the solution in well-aerated DWC remains clear throughout the crop cycle (months) indicating low microbial activity in the bulk solution.
Several water treatment technologies have been used to reduce disease. These include chlorination, hydrogen peroxide, filtration, and ozonation [102,103,104,105]. Some sanitizers can degrade chelates in solution [106]. Ultraviolet light has been used in recirculating systems to reduce microbial activity in solution and to help prevent disease [107], but UV photons break down chelates [108], and the chelates must be re-added. Acidic root zone conditions have also been shown to reduce disease persistence [109,110].
We have not found any of the above treatments necessary. Root-zone disease has been minimal in our systems, perhaps because the root surfaces are uniformly well aerated and the steady-state nutrient levels that come from the daily refill solution result in healthier roots.
 
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Dr.Dutch

Well-known member
Correction and clarification on the H2O2 point – conclusion still stands: It has no place in nutrient solution.

The Impact of Adding H₂O₂ to a Plant Nutrient Solution Containing EDTA​


Adding hydrogen peroxide (H₂O₂) to a nutrient solution with EDTA affects the chemical stability, micronutrient availability, and plant growth in several ways:


  1. Oxidation of the Iron Complex (Fe-EDTA):
    • Iron is often supplied as Fe-EDTA to remain soluble and plant-available.
    • H₂O₂ oxidizes Fe²⁺ in the complex to Fe³⁺:
      1733933996841.png
    • Fe³⁺ is less available to plants than Fe²⁺ due to its reduced cellular uptake.
    • Further reactions may destabilize the Fe-EDTA complex, leading to iron precipitation (e.g., as Fe(OH)₃), reducing iron availability.
  2. Radical Formation and Oxidative Stress:
    • The Fenton reaction between Fe²⁺ and H₂O₂ generates hydroxyl radicals (HO⋅HO^\cdot), which can:
      • Degrade EDTA, compromising its chelating ability.
      • Oxidize other micronutrients like manganese (Mn), copper (Cu), or zinc (Zn), altering their availability.
      • Oxidize organic substances, such as amino acids or humic substances, reducing their efficacy.
  3. Antimicrobial Effects of H₂O₂:
    • H₂O₂ acts as a disinfectant, reducing harmful pathogens like fungi or bacteria in the nutrient solution.
    • However, this antimicrobial effect is limited at low concentrations tolerable for plants and diminishes quickly as H₂O₂ decomposes.
    • High concentrations may harm beneficial microbes, such as Rhizobium or Bacillus spp., disrupting symbiotic processes crucial for nutrient cycling.
  4. pH Alterations:
    • The reaction of H₂O₂ with Fe-EDTA produces hydroxide ions (OH−OH^-), increasing the pH of the solution.
    • A higher pH can further reduce the availability of micronutrients like iron, manganese, and zinc, as they tend to precipitate under alkaline conditions.




  • Findings on Plant Growth:
    • Lettuce: Shoot fresh weight was significantly greater in control and 3% hydrogen peroxide treatments. Higher concentrations of PERpose Plus and ZeroTol restricted plant growth.
    • Basil: Only cultivar differences for SPAD and plant width were reported.
  • Findings on Algae Growth:
    • Algae growth was not significantly controlled by any treatment based on algae counts, weights, or spectrometer readings.
    • However, algae species quantification showed significant reductions in Microspora tumidula concentrations with hydrogen peroxide treatments.


Findings:
  • Plant Growth: Conventional fertilizers with H₂O₂ led to stunted growth or death of lettuce plants. However, 37.5 mg/L of H₂O₂ with organic fertilizers resulted in yields comparable to conventional fertilizers without H₂O₂.
  • Dissolved Oxygen (DO): H₂O₂ increased DO levels in the root zone, but its effects diminished over time. Organic treatments showed more drastic swings in DO levels.
  • Fresh Weight: The highest fresh weight was observed in the control with conventional fertilizers. Organic treatments with 37.5 mg/L H₂O₂ had similar yields to conventional treatments without H₂O₂.
  • Root Length: H₂O₂ significantly decreased root length, especially in conventional treatments.
  • Leaf Width and Plant Height: Higher concentrations of H₂O₂ reduced leaf width and plant height, particularly in conventional treatments.
 

DARKSIDER

Official Seed Tester
Moderator
ICMag Donor
Veteran
Hydrogen peroxide (H₂O₂) is a clear and somewhat acidic liquid made up of two oxygen and two hydrogen atoms. 1 Food-grade hydrogen peroxide refers to 35% concentrated hydrogen peroxide. It's known as “food-grade” because it doesn't contain particular stabilizers that are harmful if ingested

I use food grade and also pumps running in my rezes for cleaning in a way and also mixing nutes always moving the water around whatever works best for me and my ladies but then again im not in Coco Coir ;)
 

Ca++

Well-known member
I have used it plenty on coco. The idea coco can't be over watered is being used to suggest the h2o2 isn't needed. However, a coco grower knows this isn't so. They make efforts to aerate the coco further, such as pebbles or perlite quite often. There is always a need for more oxygen in the water, even in aeroponics.

I use coco mostly for rooting. I fill the 40 cell seed tray, wet it, and it's still wet 2 weeks later. They love a bit of h2o2 in them early feeds, when it's going to last for days.
 

Dr.Dutch

Well-known member
I have used it plenty on coco. The idea coco can't be over watered is being used to suggest the h2o2 isn't needed. However, a coco grower knows this isn't so.
No, I've been growing in coco for three years, and you can't overwater good-quality coco.

Good coco = Not too fine in structure and mixed with perlite (mixing coco with perlite is so standard that it hardly needs mentioning – at least in my case).

With that, you get a water retention capacity and air porosity in the substrate that, even when freshly watered, still allows more than enough oxygen to reach the roots.

Overwatering is simply a lack of oxygen at the roots, nothing more.

They love a bit of h2o2 in them early feeds, when it's going to last for days.
Adding H2O2 to coco results in a direct reaction with the organic matter in the coco. It doesn’t affect the plants in any other way. Sorry, but this is pure bro science regarding any benefits of h2o2 for plants, when you add it to the substrate.
Spaying it seems to have some positive effects.

Hydrogen peroxide (H₂O₂) has several documented effects when applied as a foliar spray:

  1. Stress Mitigation: At low concentrations, H₂O₂ can act as a signaling molecule, helping plants manage stress from salinity or other abiotic factors. For example, in bell peppers, H₂O₂ application improved photochemical efficiency and growth under salt stress conditions, with optimal effects at lower concentrations (e.g., 15 μM)【10】【11】.
  2. Antioxidant Enhancement: In amaranth plants, foliar application of H₂O₂ increased the production of phenolic compounds, anthocyanins, and antioxidant capacity. Moderate concentrations (e.g., 125–250 mM) enhanced the accumulation of beneficial metabolites without adversely affecting plant growth【10】.
  3. Improved Photosynthesis: In soursop plants, H₂O₂ improved gas exchange parameters, stomatal conductance, and quantum efficiency of photosystem II, especially under saline irrigation. These effects highlight its role in maintaining photosynthetic efficiency under stress【12】.
  4. Potential Risks at High Concentrations: Excessive H₂O₂ levels can cause oxidative stress and harm plant tissues. For instance, in some studies, high doses intensified stress effects rather than mitigating them【11】【12】.
 

DaEarl73

Well-known member
@Ca++ recommended it to me and helped me safe my crop, 100ppm of h2o2, otherwise the plants would have had a very hard time. I still put it in early vegetation and leave it later. The plants love it! Thanks again, you helped me safe my genetics! Thanks for the info spread here too, appreciate it! Have a nice one
 

strain_hunter

Well-known member
@Ca++ recommended it to me and helped me safe my crop, 100ppm of h2o2, otherwise the plants would have had a very hard time. I still put it in early vegetation and leave it later. The plants love it! Thanks again, you helped me safe my genetics! Thanks for the info spread here too, appreciate it! Have a nice one
Should I use it in my soil grow too or is it only for coco? Have H2O2 here.
 

Dr.Dutch

Well-known member
@Ca++ recommended it to me and helped me safe my crop, 100ppm of h2o2, otherwise the plants would have had a very hard time.
Already a rate that is toxic to plants :rolleyes:

And yeah, this is hilarious. Even at 3% H2O2, there’s no effect on algae at the roots :ROFLMAO:
Hydrogen peroxide (H2O2) is a well-known oxidizing agent often used as a remedy by consumers to treat algae and root decay from presumed root disease on interior plants, as well as to encourage root growth and health. To characterize the phytotoxic effects and define the safe concentration threshold for H2O2 use on ‘Vivaldi’ hybrid phalaenopsis orchid (hybrid Phalaenopsis), root systems were dipped for 3 minutes in 0%, 3%, 6%, or 12% H2O2 one time and observed in greenhouse conditions for the following 27 days. Root systems of each plant were assessed over time for percent visible root damage; ratings of root health on a scale of 1 to 5 points, with 5 points indicating “very healthy”; and final fresh and dry weights. To determine when symptoms manifested above the root zone, foliage and flower damage was evaluated over time by assessing percent visible foliage damage, ratings of foliage health, percent foliar wilt, flower/bud count, and final foliage and flower fresh and dry weights. Over the evaluation period, the root health rating of the ‘Vivaldi’ hybrid phalaenopsis orchids treated with 12% H2O2 decreased from 5 to 1.13, whereas those treated with 3% H2O2 only decreased from 5 to 4.13. H2O2 concentrations of 6% and 12% damaged root health permanently, whereas the 3% H2O2 concentration only caused minor damage to overall root health. However, algae were not killed at the 3% rate



Should I use it in my soil grow too or is it only for coco? Have H2O2 here.
Nope, you shouldn't use it in soil or coco. There is enough scientific evidence showing that it has no benefits and can even be harmful to plants. Just read my last few posts here.

Everything on this site, for example, is complete nonsense. It’s not the grower scene’s fault that this myth is so widespread, I would say, but holding on to it would be unreasonable.
 

DaEarl73

Well-known member
Already a rate that is toxic to plants :rolleyes:

And yeah, this is hilarious. Even at 3% H2O2, there’s no effect on algae at the roots :ROFLMAO:



Nope, you shouldn't use it in soil or coco. There is enough scientific evidence showing that it has no benefits and can even be harmful to plants. Just read my last few posts here.

Everything on this site, for example, is complete nonsense. It’s not the grower scene’s fault that this myth is so widespread, I would say, but holding on to it would be unreasonable.
I get your post and appreciate it. I just wrote what I saw, and thanks to ca++ I was able to save my plants! Call it broscience or whatever, but without that tip I would have lost some loved plants. Just my 2 cents, don’t want to discredit science! Thanks for the links!
 

spacetraveller

Active member
What up y all!:smoke:

Bubbling the reservoir with an air pump and some stones 15 min prior to each watering event, yay or nay?
I also have a stirring pump that run togheter with the air pump.....
Hey Gfr,

Aerating the reservoir is mainly for outgassing purposes, to stabilise the ph.
There is a complex acid- base interaction when we mix a brew for our plants, causing carbon dioxide to form in the mix and carbonic acid production. CO2 is highly unstable in aqueous solutions and is easily outgassed to stabilise matters somewhat.
It is also worth considering the alkalinity of your base water, as this has a major bearing on stability, rather than the use of further acids to change the ph.

Peace!
 

Dr.Dutch

Well-known member
I overwatered them in rockwool, the h2o2 helped them survive and me to cut clones of them and carry on. Saved me and the roots seemed to like it
No, the H2O2 didn't help you there. They would have recovered on their own anyway.

I’m surprised that you managed to overwater rockwool. Did you leave the irrigation running continuously with drip-feed, or how did you even get there?

Rockwool has a water retention to air porosity ratio similar to coco/perlit, meaning it’s practically impossible to overwater unless it’s perpetually soaked (thats why these substrates are used in hydro).

And the solution would be simple: let it dry out a bit, allowing air with its 200,000 ppm oxygen to enter the substrate (rockwool contains about 30% air after the water drains, as said similar to coco/perlite). This ensures there’s enough oxygen at the roots again.

The approximately 20 ppm of oxygen dissolved in water are irrelevant when growing in substrate—thinking otherwise is absolute bro-science if you’re trying to get oxygen into the medium that way. Watering again just worsens the situation instead.
 

CocoNut 420

Well-known member
The whole oxygen thing appears to be blown way out of proportion?
20241002_123034 (2).jpg
2 months ago and more I put them in bags to keep gnats in/out.
20241002_123034 (2).jpg

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20241205_154206.jpg

They've not missed a beat something doesn't add up?
 

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flylowgethigh

Non-growing Lurker
ICMag Donor
Should I use it in my soil grow too or is it only for coco? Have H2O2 here.
Rain water has natural H2O2 and the rain is fully oxygenated. My water comes from the ground and then the water dept puts in chemicals. I draw. Water for my reservoir from the hot water tap because the chem smell goes away in the water heater. I also have carbon filtration for the house but I suspect the filters don’t last long because I can smell the chems in the cold water. The water from the tap is oxygen deficient, thus having a bubbler in the reservoir, and doing the waterfall thing when I add water to the reservoir. The pH gets adjusted down to around 6.4, and cal-mag is added.

Seems to make the soil grown plants happy… 11 daze from flip:

image.jpg
 

Dr.Dutch

Well-known member
The whole oxygen thing appears to be blown way out of proportion?
This is easy to explain: Less than 20 ppm of air in water is sufficient, as can be seen in any DWC system.
Air, as mentioned, contains 200,000 ppm, which is 20,000 times more than what can dissolve in water.
In a substrate containing air, oxygen constantly diffuses from the air into the water when the roots consume the oxygen there.
In your case:
  1. There is more than enough air in the bags,
  2. The bags are unlikely to be hermetically sealed, and
  3. I assume you open them occasionally for watering

Rain water has natural H2O2 and the rain is fully oxygenated.
Yeah, one of the bullshit claims why one should add h2o2 to the water.
Rainwater typically contains hydrogen peroxide (H₂O₂) in concentrations ranging from 0.5 to 5 ppm. These levels depend on environmental factors such as air pollution, UV radiation, and the presence of ozone. In highly polluted areas or under intense sunlight, the concentrations can be higher.

The H₂O₂ content in rainwater plays a role in atmospheric cleaning, as it releases reactive oxygen species that help break down pollutants.
This dose is harmless, but would also do nothing to your nutrient solution.

My water comes from the ground and then the water dept puts in chemicals. I draw. Water for my reservoir from the hot water tap because the chem smell goes away in the water heater. I also have carbon filtration for the house but I suspect the filters don’t last long because I can smell the chems in the cold water. The water from the tap is oxygen deficient, thus having a bubbler in the reservoir, and doing the waterfall thing when I add water to the reservoir. The pH gets adjusted down to around 6.4, and cal-mag is added.
Ok, sounds all like a good setup for a dwc

Seems to make the soil grown plants happy… 11 daze from flip:
And nope, you don't need a bubbler for soil^^
 

Orange's Greenhouse

Active member
@Dr.Dutch did an AI write that wall of text for you?
The chemistry equation is wrong. EDTA hinders the reaction between iron and H2O2. Formation of iron hydroxide is pH dependent and not related to ORP.
H2O2 does reduce CFU count in low doeses and does not impact growth. The paper you linked and the science in hydroponics blog you linked both say so.

Oxygenating feed water is beneficial in soilless substrates. They even sell machines to oversaturate the water.
And stop confusing people by throwing numbers around. 200.000 ppm oxygen in air is meaningless because the root will never be in contact with it. There is always a water layer into which it has to diffuse before it is available to the root. And more likely than not a root in contact with air dries out rather than benefiting from it.

This is just what I found at a glance. But you make many more claims at a rate that is way too high to debunk them all. I'm out.
 

Nannymouse

Well-known member
It's confusing. Water IS oxygenated. Any more oxygen, and it isn't water, anymore. If it is PURE water, the container is free of contaminants, the air is free of contaminants, water doesn't need anything, it's still water.

If it loses oxygen, it isn't water anymore.

Start with that.
 

Ca++

Well-known member
No, I've been growing in coco for three years, and you can't overwater good-quality coco.

Good coco = Not too fine in structure and mixed with perlite (mixing coco with perlite is so standard that it hardly needs mentioning – at least in my case).

With that, you get a water retention capacity and air porosity in the substrate that, even when freshly watered, still allows more than enough oxygen to reach the roots.

Overwatering is simply a lack of oxygen at the roots, nothing more.


Adding H2O2 to coco results in a direct reaction with the organic matter in the coco. It doesn’t affect the plants in any other way. Sorry, but this is pure bro science regarding any benefits of h2o2 for plants, when you add it to the substrate.
Spaying it seems to have some positive effects.

Hydrogen peroxide (H₂O₂) has several documented effects when applied as a foliar spray:

  1. Stress Mitigation: At low concentrations, H₂O₂ can act as a signaling molecule, helping plants manage stress from salinity or other abiotic factors. For example, in bell peppers, H₂O₂ application improved photochemical efficiency and growth under salt stress conditions, with optimal effects at lower concentrations (e.g., 15 μM)【10】【11】.
  2. Antioxidant Enhancement: In amaranth plants, foliar application of H₂O₂ increased the production of phenolic compounds, anthocyanins, and antioxidant capacity. Moderate concentrations (e.g., 125–250 mM) enhanced the accumulation of beneficial metabolites without adversely affecting plant growth【10】.
  3. Improved Photosynthesis: In soursop plants, H₂O₂ improved gas exchange parameters, stomatal conductance, and quantum efficiency of photosystem II, especially under saline irrigation. These effects highlight its role in maintaining photosynthetic efficiency under stress【12】.
  4. Potential Risks at High Concentrations: Excessive H₂O₂ levels can cause oxidative stress and harm plant tissues. For instance, in some studies, high doses intensified stress effects rather than mitigating them【11】【12】.
Well I'm quite amused. You say coco can't be over watered, but you always add something for aeration. Something we can't quantify. So really this is meaningless, except enforcing what I said, about coco growers knowing it can be over watered. Though you don't seem to know you are saying this. Or lots of other things actually. I'm really not prepared to have a chat with AI until it's finished school. It always looks like a convincing answer, and if you had to ask, then chances are you will believe it. However, it's just not reviewed. It's a fancy google search compilation. It understands nothing.
 
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