DWC, RDWC –Can you diagnose low dissolved oxygen in DWC / RDWC before the roots suffocate and die?

[Arthur]

Interesting vid, guy pumping pure O2 into his systems.

Not sure it's cost effective...but interesting.

(Edited due to stoner fingers)

 

[Arthur]

@Ash-a-Ton different brand, but a good comparison.

(Edit) not a bubbler, but same principle of adding O2




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[Henry]

Ran across this piece about DO the other day.
Understanding Dissolved Oxygen, by Kurt Becker, 1/29/2016https://www.growertalks.com/Article/?articleid=22058

Of course this is not for hobby growers at all. Did find this interesting enough to read the whole piece though. Most hobby growers clearly have little to no interest in DO for some reason, maybe it's too complicated, too much trouble to deal with, treating Pythium caused by root suffocation is easier than preventing root suffocation from low O2 in res water…


Regarding the cost for DO Testing: Salifert O2 Test Kit http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=16555&cmpid=03cseYY&ref=6194&subref=AA&cmpid=PLA_G_6194&gclid=Cj0KEQiAsrnCBRCTs7nqwrm6pcYBEiQAcQSznOTuM2_ltCSX1xoR9NCPpBBx2OGhKMP8Qgsk4aN4tRoaAkd_8P8HAQ

50 DO Tests cost $19.99 Each DO Test cost $0.40 per test+ FREE SHIPPING

Although these little DO test are much cheaper than a DO Meter, does anyone here have a clue how to identify a low DO test, what the DO Test results actually mean or how to increase the DO to safe value. What is a safe DO Saturation? All this DO stuff is very complicated, hard to comprehend.

You know, like how low does the DO Saturation have to get to suffocate cannabis roots in DWC, kill roots and invite Pythium fungal outbreaks?

Everyone knows the routine after a Pythium outbreak is discovered in DWC/RDWC; CRISIS - quickly brew teas, add H2O2, Clorox, fungicides, hope for the best, replant… try again.

 

[Rev. Green Genes]

The only way I know to minimize pythium is regular cleaning of equipment and careful air intake filtration. The stuff lives everywhere. Best advice is prevention, once you have it your about done unless you were lucky to catch it very early. It's not really objectively solvable. Clorox will not get all the way through the tubes and every corner of the pumps, etc. It will only kill whats present in the rez, and you get reinfection. It has traditionally been thought of as an environmental problem, rather than a specific pest because the only true control is prevention and cleanliness. UV light will kill it on contact, but again you can't get it all. There are a few bacterial remedies too, Serenade fungicide is one of them. The chlorine based products for pythium also usually have a shelf life. Pyth Tabz are a solid chlorine based additive that gets good reviews. Keep RH under 60, and temps under 70, and it will not like your space anyway, even if present it will not cause damping off without the right conditions.

 

[Henry]

There are many effective methods used to kill fungi, but the presence of fungi is very normal in all DWC, RDWC environs, as normal as the sun rising and setting every day. Although the fungi are ubiquitous in DWC, they are not an issue until the environmental conditions are perfect for colonization. When the DWC environmental conditions are right and there is plenty dead roots available to eat, they do thrive and the massive fungal colonies become clearly visible without a microscope.

Fungi are necessary and do have purpose on earth. They are opportunist they clean up death and decay and they do have a proven method of infestation/colonization. They have here billions of years cleaning up death, (proto-man to modern man have been on earth only 4.5 million years and change). Fungi do not thrive and colonize unless they have plenty food to feed the young and their colonies. Without plenty food (sick roots, dead roots and dead beneficial microbes) plus, ***a low oxygen environment which is the key ingredient in the reservoir water, the fungi cannot, will not and do not thrive in a DWC, RDWC even when the water temperature is 80F.

This is interesting: https://www.mjguide.com/tutorials/PlantTrouble/1289.htm “The [most vital 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.”

Root suffocation, death and decay come first making the fungal outbreaks possible.

 

[Rev. Green Genes]

https://www.autoflower.org/threads/...other-issues-as-well.43164/page-2#post-846875

notice in the root rot photos how above the water line is clean, and below is brown. That is likely due to poor aeration on top of high humidity and temps. A chiller and better aeration will stop it before it starts. It is worth considering where your air pump is getting it's air from as well, mind the intakes.

If you can catch it at that point, and remove the dead roots, treat the clean roots, and put it into a sterilized reservoir (including tubing) you can save a harvest, but it will put a lot into root development, and be stunted if it is still in veg, it will take a week or more recovery.

 

[puggle6]

Can I suggest that if you don't have access to serious engineering and or knowledge then don't play with pure gasses!



Darwin takes over lol

f6

 

[Henry]

Can I suggest that if you don't have access to serious engineering and or knowledge then don't play with pure gasses!



Darwin takes over lol

f6

Right…. particularly ozone, hydrogen, 5% CO2, ether or nitrous oxide.

 

[Henry]

Interesting vid, guy pumping pure O2 into his systems.

Not sure it's cost effective...but interesting.

(Edited due to stoner fingers)

Don’t know about cost effective, but I have seen warning signs in hospitals posted on doors where Oxygen in being used in patients rooms that say, “NO SMOKING - OXYGEN IN USE”.

Is smoking a joint safe around oxygen safe?

 

[Arthur]

Don’t know about cost effective, but I have seen warning signs in hospitals posted on doors where Oxygen in being used in patients rooms that say, “NO SMOKING - OXYGEN IN USE”.

Is smoking a joint safe around oxygen safe?

ABSOLUTELY NOT!
NEVER EVER!