Dissolved Oxygen Meter Testing

[allouez]

Cool stuff. Thanks Stedenko! Am I reading this wrong, or on these results is there no sign at all that the aeration actually did anything? Besides the plain tube. Looks like the tap water was saturated from the start and just kept declining very slightly, with an immediate boost from the plain tube and immediate loss once stopping the plain tube.

Can't wait to see how the next round of testing goes

 

[Scrogerman]

How about a couple of these, or a DIY version, looks like it could be simple to replicate, check these out: http://www.hydroponics.eu/nutrients...y-s-88/oxydator-big-grow-technology-1775.html

I like it pushes more O2 out as it gets warmer,mmm.(ponders!!) I want a few, but look at the fkin price of them, anyone fancy doing a DIY tute? gotta be one way to go, what you think Sarge? potential?

 

[Sgt.Stedenko]

The problem I see for a DIY, is liquid oxygen is a liquid only when it's below -180C. Above that, and it sublimes into gaseous oxygen. You would need an insulated vacuum bottle (dewar) to keep the LOX in it's liquid state. The tech is out there from the medical field for people who need portable oxygen tanks. Adapting it to a hydro setup is the trick.
The "liquid oxygen" the vendor is selling in bottles is some voodoo bs, imo. Unless the laws of physics dont apply to their product. It's not true LOX, otherwise it would be gaseous at STP.

 

[Scrogerman]

That doesnt apply to H2o2 & the Oxydator, i wasnt keen on the pure Liquid O2 idea myself.
I was surprised to find out how much pure unstable O2 is released by H2o2 per litre, its alot of O2 iirc.(the stronger sols).

 

[Scrogerman]

A 3% solution of Hydrogen Peroxide is sometimes called ten volume strength, (one volume of Hydrogen Peroxide releases ten volumes of oxygen when it decomposes). A pint of the food-grade 35% solution contains the equivalent of 130 pints of oxygen. A pint of 3% hydrogen peroxide found at a local drugstore contains 10 pints of oxygen. A pint of the 6% solution, used to bleach hair, contains 20 pints of oxygen. When kept in the absence of light and contaminants, it dismutates (breaks down) very slowly at the rate of about 10% a year. Storing the hydrogen peroxide in the freezer slows this process.

Source: http://www.drinkh2o2.com/

I think the use of Oxydators could be a worthy test, shame their so expensive.

 

[Sgt.Stedenko]

According to several Koi and pond forums, the Baquacil oxidizer is the cheapest form of H2O2 out there, and most every town with a swimming pool supply store carries it. Those guys use it as an algicide and to elevate DO.
It can get tricky ordering strong oxidizers over the web. There are DOT shipping restrictions for the stuff, especially in quantity. My 1 gal bottle came enclosed in a plastic bag to prevent leaks. The bottle states you should not store it near flourescent bulbs.
I will warn those not used to playing with strong oxidizers, the stuff will burn you and eat holes in your clothes if not careful. And NEVER let the stuff get near any sort of hydrocarbon, unless you like visits from the fire department.

 

[Scrogerman]

So what about the H2o2 Oxydator tec then Sarge? its different to actual Liquid O2, but its still pure water with a pure O2, & thats my main attraction to it, peroxide can be a missleading rep of it as its acctually Dioxide by rights. Anyway i bare wittness to using H2o2 with mineral based nute lines/boosters, i see/visually such a growth boost with its use, its obvious its the DO increase doing this/increasing nute uptake. G'Luck with more experiments Sarge, i hope you add a couple of those Oxydators to the tests, it would be really helpfull making a decision to get a few, or copy the tec. They look like they have potential to me.
Cheers Guys!

 

[Sgt.Stedenko]

Looks like the Growth Technology Liquid Oxygen is 17.5% H2O2.
http://www.growthtechnology.com/downloads/sds/sds-liquidoxygen.pdf
If I could get a better idea about how the dispenser works, I might be able to make one.

 

[Scrogerman]

What it says about the Grow Technology Oxydator Bigi couldnt resist bro)

The problem with Liquid Oxygen, if it has one, is that it is so volatile.
It can be added to the tank daily but it only remains active for quite a short time – a few hours at most. This is because it is unstable and this is why it works so well of course. However growers have always dreamed of being able to maintain a constant level in the tank for this would be the only way to ensure against pathogenic intrusions over the life of the crop.
Oxydator is a self-regulating Liquid Oxygen doser; with a constant slow release, meaning no more wastage of the product and optimum levels maintained continuously in the tank.
This compact unit just sits in the tank and, when filled with Liquid Oxygen, delivers a continual stream of pure oxygen into the tank.
•Continuous delivery of unstable oxygen which will destroy fungal spores and disease organisms. More units can be simply added for extra protection or for larger tanks.

•Allows the full use of GreenFuse and other organic additives without any problems.

Increases in activity as tank temperature rises – thus delivering the maximum oxygen when it is most needed.

Promotes a clean, disease free tank and highly oxygenated nutrient which will help to ensure healthy roots and deliver explosive growth.

One of the biggest overlooked ways to max out nute uptake invho, 'Just 'DO' It'. Forget organic boosters & snake oils.
Full mineral based nutrition, Pk boost & loads of DO for max nute uptake is all thats needed, i think DO is very overlooked in Hydroponic systems, & more & more people are going hydro organic(using organic based addys etc), when theres absolutely no need whatsoever. But as H2o2 dissipates out of solution every 24 hours approx, theres room for organics/stress relievers etc if required(right before any change-out), but mostly they aint nessasary. Esp in water culture growing /NFT etc etc.

 

[Scrogerman]

Looks like the Growth Technology Liquid Oxygen is 17.5% H2O2.
http://www.growthtechnology.com/downloads/sds/sds-liquidoxygen.pdf
If I could get a better idea about how the dispenser works, I might be able to make one.

Ahhh, Now your talking brah!

 

[Sgt.Stedenko]

Some aquarium geeks have made a DIY Oxygenator using peroxide and lead as the catalyst.
http://www.coloradoaquarium.org/pics/oxy.html
Basically, an oxygen bubbler. Not sure if this will supersaturate the water it's placed in, or just lead to standard saturation levels.
I'll make one up and do some testing. I've got a small lead fishing weight in a cup of peroxide, and it definately make a steady bubble stream of O2. The problem I see is the reaction is highly exothermic. The peroxide is up to 130F after 20 minutes. Probably not good for a res which we strive to keep cool.

Edit. The lead in the peroxide is still bubbling after 6 hours, but not as vigorously. The exothermic reaction lasts about 1/2 an hour.

 

[Scrogerman]

Sounds interesting Sarge, not the exothermic lead reaction, not sure on the implications there like you said but it dont look too clever at those temps lol. But it does look usefull as an external O2 Bubbler, for sure. Cheers man!

I mentioned on another thread about a H2o2 bubbler, which is similar tec to the Oxydator, i was thinking similar to a Co2(DIY) Bubbler, like the ones you see about with airstones & pumps etc. steady stream of O2 seems to be the path, to keep up the DO levels. Makes H2o2 use much more useful/longer term.
Your link explains it well.

Cheers Bro!

 

[Kcar]

You can get a 20lb fill of compressed O2 for like $18-$20 in a regular old tank.
We do it all summer long to keep our live bait from dieing.

The guys that drive live fish all over the bay area use LOX, in a big 50gal pressure
vessel on the back of their truck. (LOX also helps keep the water cold...)

 

[luv2grow]

sgt, if you havnt seen a diagram perhaps this will help re the oxydator..
http://aquariumoxygenator.com/
im trying to hunt down the patent information it would make things easier regarding the best catalyst to use, and hopefully give some technical details.
its a simple device really, the catalyst and h202 generates the o2 , the amount and type of catalyst, strength of h2o2 and water temp regulates the output.
the catalyst regenerates itself, more or less

*edit* the ceramic part may be acting as a molecular sieve of some description.

as demand increases when the plants grow, youd be able to use a more conc solution of h2o2 to compensate? (i envy your DO meter) lol

im gonna get one anyway, the oxydator, once i work out guranteed safety parameters. im petty much sold on the thought.
keep up the good work.
peace

 

[Haps]

Cool stuff Sarge, thanks for the data. It is good to see numbers to match the conclusions I made years ago by watching my own crops side by side.

Roots will sometimes grow up a tube, about one in twenty here, just make sure to clean and test the tubes between grows. I use a wire or a long pipe cleaner when one clogs, easy fix. I have never had roots cut the do off in any of my buckets, about 4 years now.

H

 

[thefatman]

The bare tube causes more surface agitation than a airstone. The majority of oxygen exchange is at the air water interface (waters surface). The advantage of airstones for anything but root movement and water movement only really comes into play when there is a limited air water interface. When there is a limited air water interface then the airstone with the finer bubbles increases (maintains) the DO the most as the bulk of the DO is added within the water column rather than at the air water interface. Theoretically!

IMHO DO saturation is not all its cracked up to be. What is most important is insuring the DO laden nutrient water is delivered to all the roots. This seldom happens in most hydroponic systems due to poor design. Small aero tubes nearly always have root rot problems as do NTF systems as only the roots first contacted by the water receive a large amount of DO where the other roots only come into contact with the water that has already had the majority of the DO stripped by the roots first contacted. DWC systems have the same problem if there is not vigorous water movement keeping the roots from just hanging down in a tight mass where only the outer layer of the root mass contact water with a high DO.

 

[Scrogerman]

The problems i see with Tubes is the output air & surface agitation is isolated to one spot, maybe a few square inches, whereas with airstones you agitate the whole surface area, if tubes are giving more DO, then imo the pump isnt big enough. see where im going there?
When i use my Kam-Air 70lpm compressor pump & 6 x 12" ceramic airstones, my 70litre tote is like a Jucuzzi. The surface agitaion looks like a bubbling white water rapid/river.

Hey fatman,
How can you say DO saturation is not its all cracked up to be? I think the oppisite, imo its one of the most overlooked & underestimated ways to boost nutrient uptake & growth. Its well known Canna can use much more DO than can be applied/achieved with the use of airpumps/waterfalls through surface agitation etc.
If Canna can use 30-100ppms of DO in a solution, & we can only max-out DO at around 9ppms at 68f, dont you think we as Hydro growers are missing out on something?.

I know when i add H2o2 to my Res, i see a real growth boost 'Visually', we know this boost comes from DO boosting nutrient uptake. Id like to see how far i can go with this & get upto the DO level Canna is known to be able to use.
More DO, More Nute Uptake, More growth, its a no-brainer to me man.

Im of the opinion, all we actually need to achieve maximum growth potential is a full balanced mineral nutrition & as much DO as can be achieved(upto 30-100ppms), & adding PK & or other mineral elements as required by growth phase/plants.
(providing we have optimal environment-of course!!!)
We dont need all these snake oil products the likes of AN are trying to ram down our necks, to achieve this.
Imo DO is the missing link & is Very overlooked. Anyone who uses H2o2 will surely attest to the growth boost they get from increasing DO levels.

btw, ive run NFT for years & never had root-rot once. The beauty of NFT is the system naturally creates a system of air-roots that sit above the nutrient film, so roots in NFT have constant access to air, different to DWC, which ive also ran for years.

Organics in Hydro or Hydro-Organic is relitively new imo, & it seems to me Manafacturers of Nutrients & Additives have for the last 20 years been pushing us all to use more & more organics in our hydro solutions. These Organic additives/nutes etc, are not nessasry in hydro & can give room to cause infections/pathogens to bloom. I see people having issues all the time. Full mineral nutrition & High DO to create a high aerobic environment is all thats needed for maximum growth. In future when i run hydro, im sticking to mineral based nutrition & H2o2, its all a hydro grower really needs for a trouble/pathogen free grow with max growth potential, because of elevated & optimal levels of DO. Im a believer!

G'Luck Guys!

 

[Scrogerman]

sgt, if you havnt seen a diagram perhaps this will help re the oxydator..
http://aquariumoxygenator.com/
im trying to hunt down the patent information it would make things easier regarding the best catalyst to use, and hopefully give some technical details.
its a simple device really, the catalyst and h202 generates the o2 , the amount and type of catalyst, strength of h2o2 and water temp regulates the output.
the catalyst regenerates itself, more or less

*edit* the ceramic part may be acting as a molecular sieve of some description.

as demand increases when the plants grow, youd be able to use a more conc solution of h2o2 to compensate? (i envy your DO meter) lol

im gonna get one anyway, the oxydator, once i work out guranteed safety parameters. im petty much sold on the thought.
keep up the good work.
peace

This is a great link man, perfect.!
I wonder if we could custom enhance these Oxydators, using a heating mat & airstone/bubbler of some-sort to increase O2 output, mmmm? warmer it gets the more Pure O2 they push out.

Does anybody know the amount of DO(ppm) aerobic bacteria can tollerate, before DO's oxidising abilities kick in & kill them>?

 

[allouez]

IMHO DO saturation is not all its cracked up to be. What is most important is insuring the DO laden nutrient water is delivered to all the roots. This seldom happens in most hydroponic systems due to poor design. Small aero tubes nearly always have root rot problems as do NTF systems as only the roots first contacted by the water receive a large amount of DO where the other roots only come into contact with the water that has already had the majority of the DO stripped by the roots first contacted. DWC systems have the same problem if there is not vigorous water movement keeping the roots from just hanging down in a tight mass where only the outer layer of the root mass contact water with a high DO.

I don't understand. If the oxygen is dissolved, I thought that by definition the oxygen is distributed evenly in the solution? Especially if it's saturated... if the roots were taking in oxygen faster than the oxygen could distribute evenly, wouldn't the solution be well below saturation?

 

[Scrogerman]

I cant say i agree with Fatmans take on how roots deal with DO/or the solution.
Plants have different kinds of roots in different levels in the rootzone, & that isnt being considered here, it depends on the system config/media etc. Ive done alot of NFT so i know exactly how it rolls, never had an issue.

Theres diagrams somewhere showing how roots operate in these systems, ill go see if i can find some.