Oxygen generator vs air stone? Concepts and DIY approaches.

Found this little tidbit online, thought it was interesting, especially the last bit:

Dissolved oxygen levels in tap water are typically between 5-7 parts per million (PPM) at room temperature. Temperature has a powerful effect on how much oxygen can be held by water molecules. The warmer the water is, the less gas it is able to hold. Fully oxygenated water at 68° Fahrenheit will hold about 9 PPM of DO, while the same water at 86° Fahrenheit only holds about 7.5 PPM (over 15% less DO). It should come as no surprise then that the ideal temperature for maximizing root growth in hydroponic systems is 68° Fahrenheit, the temperature at which water naturally holds the 8-9 PPM of DO, which is the very amount of DO necessary to support vigorous plant growth in most crops. Water holds both dissolved solids like fertilizer as well as dissolved gases like CO2 & O2. The higher the PPM (dissolved solids), the less gases water can hold, so be aware that over fertilizing often occurs in conjunction with oxygen deprivation.

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I would love to do some experiments with an accurate meter to see how well saturated the nutrients can get with various methods and how much of a difference a 1000 ppm nutrient mix makes in the saturation point. I very much suspect that the saturation limits are much easier to reach that most growers would imagine. The key is nutrient temperature.

I think I will be getting a new tool to play with (Photometer HI83300) and this little experiment would be another use for it. Right now I am kinda holding off on buying anything until the corona virus thing dies down. Heck for all I know the company could go out of business or their prices could drop or something better may come out.

Renfro said:

Found this little tidbit online, thought it was interesting, especially the last bit:

I would love to do some experiments with an accurate meter to see how well saturated the nutrients can get with various methods and how much of a difference a 1000 ppm nutrient mix makes in the saturation point. I very much suspect that the saturation limits are much easier to reach that most growers would imagine. The key is nutrient temperature.

I think I will be getting a new tool to play with (Photometer HI83300) and this little experiment would be another use for it. Right now I am kinda holding off on buying anything until the corona virus thing dies down. Heck for all I know the company could go out of business or their prices could drop or something better may come out.

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Room temperature in south florida is a lot different than room temp up north, and then there's seasonal "room temps" so...?

Check out O2Grows website. You might get some useful 411 there, but they're pretty tight liped regarding MJ

When I ran DWC I had a gut feeling that the roots weren't only benefiting from DO saturation but the fact the air bubbles are going up through the roots provides ample supply of non dissolved oxygen.

What it comes down to...... Is your plant come to life with right balance. o2, nutrients, environment, all of it.

Renfro said:

https://lakestewardsofmaine.org/wp-content/uploads/2014/01/Maximum-Dissolved-Oxygen-Concentration-Saturation-Table.pdf

http://dep.wv.gov/WWE/getinvolved/sos/Documents/SOSKit/DOSaturation.pdf

There used to be a really good read that I had found like 16 years ago but I can't find it now. Basically the limit is low and easy to achieve by simply disturbing the water surface with a water fall or floom.

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Search Structured water. Flowing water down a stream cascading over rocks is said to significantly increase DO while enhancing it

Renfro said:

When I ran DWC I had a gut feeling that the roots weren't only benefiting from DO saturation but the fact the air bubbles are going up through the roots provides ample supply of non dissolved oxygen.

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AND the air bubbles popping at the surface provide DO to the non submerged roots. When it's rocking, you will see lovely roots ABOVE the water line

Your thoughts and feelings about higher DO are correct, trust your gut.

Rain has a 22Mg/L DO ppm if you please

I can get up to 45mg/l DO.

Cost me 5k Cdn ( this price is pretty old so talk to the company/ I cannot guarantee what it will cost you.)
Many many growers all over the world have been using DO systems to boost simplicity and growth. Usually in large systems. No one tells smaller growers or anyone else for that matter. Very secretive bunch. I have been told to shut it but I can say this ..."Giah" is the mother and nano is the solution. I have spent the money for small medical sized systems and pissed away thousands and thousands of dollars. "Giah" is the way to go.

My test system/ res is so small (55gallons) that the turbulence reduces my top Do for the picture posted. Nano bubbles tend to dislike getting slammed into surfaces and tend to return to micro level and make a fun fuzz sound on the surface. That said I dont need more than 22 so I am very happy with 35-40. Another contributor of that lower number is the probe is not moving and the water in that location is slow.

With 22Mg/l DO you have a new level of optimum temp. 74f. Plants fly, no brown "goop" ! Only professionals get to use the "goop" word the rest of you have to learn latin and stuff.

I did not tell you anything and you fig this out by watching Youtube videos. Yeah, that's the ticket.

Again this is not new for the last ten years and even then there are very few people running High Do.


Reg tap water is 7-9MG/L you can call it PPM if ya want. Air stones dont increase Do they maintain it with water movement.

I found low pressure aeroponics did wonders and built 4x8 tables. Not as high Do as nano and needed a chiller to maintain a clean res. no airstones needed for aeroponics. Low pressure Aeroponics was a nice fast and clean way to grow for cheap. I used 18" deep tables and the air in the chamber was a great transfer space. If you want to keep it cheap the larger micro spray heads with simple pvc rocks. Easy to do, easy to maintain. Ill post some pics. Wont cost 5k.
I build systems for people growing their Canadian 4 plants and usually build Dwc or Aeroponic beds. I Built a few now and a little sour on how people really are.

22mg/l DO is the do of a rain drop when it hits the earth. Funny how nature always sets the rules.

I make no money from this blurb its not an advert. Their is only one guy I found that can do what I am talking about for the small guy. The larger companies can't match it and tend to be even more expensive. The system I help my customers with uses a o2 concentration unit, much better than the bottle system used by Moleaer. Moleaer units you can find advertised on youtube.


On the pic of the plants.

The roots are poor on this pic becasue the timer was a 15 /15. I was building a system not growing weed. It was intended to be easy to build anywhere cheaply, this was originaly about food systems. You need a shorter on time and longer off time for fuller growth. You get to play with that. I wont help or do it for you just wish someone had shown this info to me when I started.

The plants I used for the test were at a medical and as you can see officer it was taken in 1980 with no location data, hint my ip address is in Canada and I protect my customers as required by health canada. I dont drive to customers homes or shops and I dont bring my leash (phone).

Fig that's it, hope it helps someone else who just has to know who doesn't want to spend the thousands and thousands I have spent playing.
One last bit. This is great for food crops and will be used in Egypt and Oman in the near future. This can actually help people and keep people fed no matter where they are.

* All spelling miss takes are on purpose.

GanjaFarmerUK said:

This was my initial worry when talking to the guys at O2 grow..
Here is the exact email that I received from one of their reps..

''For some reason people think we have generated some excess hydrogen that could be explosive or harmful. The fact of the matter is most of the separated hydrogen is also re-absorbed back into the water because the molecule formulation doesn't change, ( H20 ) however the DO level increases because we convereted it to a soluble gas. Yes some hydrogen will escape, but technically not anymore than if it was evaporating like your environment does now with evaporation. You have lots of evaporation going on in those rooms. Plus you may be adding Co2. So with that said, hopefully your concerns have been addressed. Even though we are using an electrolysis concept / science, no one has done what we are doing in horticulture. Mainly because we have patents on how we use eletrolisis and our designs doing so.

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LOL That email is pretty much science free. Plus, they cant even spell electrolysis correctly and thats their whole gig.

First, evaporation does not release hydrogen, or oxygen separately. Its just water molecules. There is zero dissociation involved. It takes electrical energy to dissociate water down into H and O molecules and evaporation doesnt do it.

Secondly, for every oxygen molecule that stays in the water, there is an extra pair of H that have to go somewhere. Conservation of mass and energy apply.

Thirdly, if you are seeing bubbles, then that gas is NOT being dissolved. Its rising to the surface and going into the air.

Fourthly, just having hydrogen released into the air all by itself is not good, but if the mixture is in the correct ratio - 2 H's for every O -, there can be real explosive damage. That means a correct ratio of hydrogen to oxygen. Turns out that when you use electrolysis to break down water into H and O molecules, you automatically end up with the perfect ratio for a bomb. I know this because when I was in high school I used to take plastic baggies and connect them to the vents on a 12v battery and fill them with the gas thats released when charging. That gas is Hydrogen and Oxygen in the perfect ratio. When you set them off, it makes a very nice boom. A 1 quart baggie set off inside a medium size cardboard box will turn the box into confetti.

Fifthly, they havent mentioned the corrosion thats going on when you do any sort of electrolysis. The metal from one of the electrodes (anode) will be broken down - corroded - and metal ions will be released into the water. Thats never a good thing. It doesnt matter what type of metal, it will corrode to one degree or another. This is easy to test. Just take some copper wire, connect to a battery, and stick the two ends in a salty solution. It wont take long before you see the copper being eaten away and the bubbles of oxygen and hydrogen rising to the surface. If you have the right shape container, you can trap the gas and make little bombs for yourself. I dont recommend that in this day and age though. You could get away with a lot more back when I was a stupid teen.

Fortunately, hydrogen is light enough that it will raise much faster than the oxygen in an open container, so explosion risk is small. In an enclosed space on the other hand, it can be a real danger.

Finally this whole idea is a very bad solution looking for a problem that doesnt exist.

Thats my 2cents anyway

With a million air stones you will only reach 9mg/l in 70F water, give or take 1mg/l. My point is the water has a natural limit.

When rain water hits the earth it has around 22mg/l, call it ppm if that works. No venturi will give you 22mg/l long enough and Micro bubbles will require continuous support (Pumps that build heat) that will outweigh the benefits of the outcome.

The massive farm sprinklers that shoot water through the air have water hitting the ground at 12-15mg/l.

Currently most nano bubble "machines" require a micro bubble venturi ( white fog of bubbles) with a pump that re pumps the micro bubbles through and forces them into Nano bubbles ( clear as water cannot be seen by the naked eye).

Hammering these bubbles up against the wall of a 90 degree pipe will slowly reduce the level of nano bubbles and requires intermittent use of a nano bubble machine. For this reason a media based flood and drain system will allow for less use of the machine giving you a benefit without unreasonable heat issues. So a rockwool or easyplug system with a black and white sheet over the table to allow root growth past the medium.

Today I know of two companies making medium sized units medical growers can use. Gaia water is the company I use. I use there system with a oxygen concentrator to do most of my tests. I will post a pic if you want. The o2 machine does not provide 100% o2, more like 70% at 5 l per min. Combine two of them and you dont need to use a O2 bottle. large Canadian LP's are now testing units as well.

When you take the mg/l past 22 you can then add co2 to the water. Yes this is actually a massive benefit. Shhh dont tell but many growers have been doing this for years now. So if you are careful and keep the co2 at 20% of the water content with the o2 at 22 on the bed you will see massive growth even with 315 bulbs and so forth. No co2 needed in the air. Also uses less co2 to saturate water. In california some companies used co2 water at a ph of 3.5-4 to spray their strawberries. No mold, almost zero pests outdoor with the benefit of evil co2 augmentation. Shhh again was a secret. I have no idea if anyone has shared this yet.

Now for the soil junkies. o2 injection makes a massive difference in growth speed and gives organic growers a real edge. I have seen soil growth just shy of hydro speed. With co2 water injection outdoor can get big dense buds. California should think about that for a min.

There is a US based company who makes O2 units but I have not picked one up yet and have yet to test it. Currently they only have a video of it going to 12mg/l and that would be only micro bubbles. I will let you know when I test their unit. If someone else has tested it already please share any data you have.

Why O2? All over california growers had been stomped out by big Ag and have zero edge. This is a way (o2 and co2 injection) medium or small growers can get a extra cycle in and hang onto a bit of market share. Almost forgot, often o2 injection takes a week or so off the cycle so this is where it adds the extra yield. If you add 20% co2 to the water it slows it back down to its normal rate. I was getting a weeks ( fast hydro) growth in 3 days.

Hope it was not too hard to read and maybe you wont have to spend all the time and money I have to now have this info.

Almost forgot: Air bubbles spitting water onto roots causes a nft type effect that has major benefits, I believe this is why Aero systems are so good. Aero however do not push mg/l past full natural saturation. I dont have data to prove this, but it seems reasonable considering known data about o2 saturation, NFT, and Aero systems.

Some time this week I will take measurements on a friends 4 plant tote system. We will add spray bars to test the saturation of micro spray vs air stones. Micro spray will be continuous in the res.

Good luck

Im not sure where you are getting your information, but DO is entirely dependent on temperature, air pressure and salinity - nothing else.

No amount of aeration, injection, nano-bubbles or anything else can force extra oxygen - or C02 - into water.

This link has several charts:




At room temperature and sea level pressure - 1 BAR - you will not get more than about 9 mg/l or PPM - no matter what you do.

Even at 0 deg C, the max is still only just over 14 PPM, so I dont know where you saw 22 PPM for rain, but thats not possible unless the rain was getting pressurized somehow at altitude.

Also, when C02 dissolves in water it forms carbonic acid - which will drop your PH - because its an acid. This is even more dramatic with hard water and with some of the salts in our nutes.

You cannot force extra O2 or C02 into water over the natural equlibrium levels unless you use pressure - like C02 in soda. Open the can, and the pressure drops and the C02 fizzes out of solution.

Adding more nano bubbles, water falls, or any other type of aeration will only get you to that 9 PPM or so max DO depending on your water temp. Any extra you try to force in will just leave as fast as you try to add it. Its an equilibrium process and you cant change that.

C02 is the same way, except that it forms that unfortunate carbonic acid until it gets around to leaving the solution.

Larry3215 said:

Im not sure where you are getting your information, but DO is entirely dependent on temperature, air pressure and salinity - nothing else.

No amount of aeration, injection, nano-bubbles or anything else can force extra oxygen - or C02 - into water.

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This is exactly correct. Dissolved oxygen limits are what they are, beyond that it's just bubbles in water, not oxygen dissolved in water. And it doesn't take much agitation of the surface to get to those limits, why waterfalls are so effective.

Larry3215 said:

Im not sure where you are getting your information, but DO is entirely dependent on temperature, air pressure and salinity - nothing else.

No amount of aeration, injection, nano-bubbles or anything else can force extra oxygen - or C02 - into water.

This link has several charts:

Oxygen - Solubility in Fresh and Sea Water vs. Temperature

Solubility of oxygen in equilibration with air in fresh water and seawater (salt water) - pressures ranging <i>1 - 4 bar abs</i>.

www.engineeringtoolbox.com

Dissolved Gases in Purified Water | ELGA LabWater

Discover the impact of dissolved gases in water purification and the additional need for consideration of their impact after purification treatment.

www.elgalabwater.com

At room temperature and sea level pressure - 1 BAR - you will not get more than about 9 mg/l or PPM - no matter what you do.

Even at 0 deg C, the max is still only just over 14 PPM, so I dont know where you saw 22 PPM for rain, but thats not possible unless the rain was getting pressurized somehow at altitude.

Also, when C02 dissolves in water it forms carbonic acid - which will drop your PH - because its an acid. This is even more dramatic with hard water and with some of the salts in our nutes.

You cannot force extra O2 or C02 into water over the natural equlibrium levels unless you use pressure - like C02 in soda. Open the can, and the pressure drops and the C02 fizzes out of solution.

Adding more nano bubbles, water falls, or any other type of aeration will only get you to that 9 PPM or so max DO depending on your water temp. Any extra you try to force in will just leave as fast as you try to add it. Its an equilibrium process and you cant change that.

C02 is the same way, except that it forms that unfortunate carbonic acid until it gets around to leaving the solution.

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I get it and you are correct about co2 water. Co2 water is used becasue it is a more efficient process , better concentrations. Co2 water needs to be applied fairly quickly. As you can imagine co2 water is a great way to add co2 to plants you can't gas, outdoor. Yeah that acid is great for killing pests and mold, horrible stuff that would be even more horrible for companies selling pesticide. With high concentrations of o2 you can add co2 to the water and the roots will pick it up.

Yes, nano bubbles are just that. The science of nano bubbles are good enough for the US Army Corps of Engineers. They built one of the largest o2 generators using o2 or Speece cones. https://balancingthebasin.armylive.dodlive.mil/2019/08/23/dissolved-oxygen-injection-system-a-remarkable-success/ Many different ways to apply o2 to water. Look up "o2 cones" and do some research if you want. This has been taught in many schools for quite some time so I would suggest doing your own research. I'm just a guy on the net.

Duration in water depends and if done correctly it can last 6 hours or more. In my mind the gains are worth it. Yes temp still applies and salinity as well. That 9mg/l usually requires RO water.

I use my dissolved o2 sensor and it confirms the results ( pic already provided with a temp on it). The speed that plants grew was great, better than the tote systems I had seen and built. My experience.

I respect your disbelief, I use tools I can see and touch they give me the numbers. I could be a negative Nelly and attack every idea but instead I spent the money, bought the tools, and got the answers for myself.

My motive is the lack of information available. I literally spent thousands and thousands building many different systems and digging through forum thread after thread trying to get the info. In the end I relearned some ideas and gained knowledge in others.

Rdwc and a chiller work great and grow fast, strong yield, totes. More work on the plants requires more man hours. market share is at risk.

Hydro Sog with heavy roots needs a flood and drain to force water movement and can be adapted to help wheelchair growers to grow for themselves.

NFT if done "perfectly" is slightly better than Rdwc in certain areas of growth, not yield, my 2cents. Might have been strain dependent.

Aero is best and I built low and high pressure with chambers as well. Every new system I have seen I have already built. Tray sandwiches to make a chamber, trys with a top( showed that pic), I have done almost every style. I have not done the wheel with the light in the middle. Aero also includes a Nft effect in its process and when you leave the res under the low or high Aero it adds a benefit. I didn't take anyone's word for it and spent time and money to prove it for myself.

I wish someone had provided this info so I had something to test against, try. I even tested cool air transfer over roots in a chamber with the low pressure water spraying. I was going to use a "o2 cone" and during that process I found Nano bubbles.

My goal was a system that was best for automation and reduced hours along with keep it simple. High pressure Aero killed the keep it simple part. Low pressure jets were able to manage even weak filtering for a full 3 months of continuous use. Mixing dwc and low pressure Aero with large sized jets was as simple as aero could get, still requires cleaning of jets and always checking. I did all of this quite some time ago. I have found many other people who have also done this in Aquaponics and so forth.


You dont have to believe me I'm ok with that. However if you are proven wrong please come back and share becasue this has been a pet peave of mine. As I searched for information I encountered many dead ends and very few answers. Lots of fighting with the desire to share "ability" or hold up ego, not information. If you prove anything I have said is wrong please share that too. I'm totally ok with learning, ego is not my deal.

Cheers

Renfro said:

This is exactly correct. Dissolved oxygen limits are what they are, beyond that it's just bubbles in water, not oxygen dissolved in water. And it doesn't take much agitation of the surface to get to those limits, why waterfalls are so effective.

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My last post was way too long.

You are correct Nano or Micro bubbles are just bubbles in water. Much like High pressure Aeroponics is just water mist in air. Nano bubbles stay in the water longer than micro bubbles and if not jarred or slammed up against a pump or 90degree elbows they can stay in the water colum for a long time. There is a 2-5% loss with use of a 1100 gallon mag drive pump and two 90degree elbows. This makes for a requirement to maintain the Nano bubbles and also requires the use of a chiller to offset the heat from the pump. Lots of extra Amps needed to get the gain, not worth it for 4 plants. More of a medical size solution. If you use two o2 concentrator's 6-800 each you can achieve 100% o2 concentration in the nano bubbles. it could cost around 5-8k to do something like this, not cheap, yet.

Co2 will not stay in the water too long and needs to be used fairly quickly. A white fog of bubbles is Micro bubbles, not Nano bubbles.

The big question is the technicality of dissolved o2 vs Nano air bubbles. These Nano o2 bubbles are full of 70-90% o2 vs Air that comes with all sorts of other goodies. For the plant is their a difference or can the plant benefit from these Nano bubbles? So far My outcomes have said this works very nicely with many many benefits.

So far the benefits from observation with no real scientific method is 20-30% increase in yield. I was also able to run at 74f with zero slime. That temp has to be a part of the growth gain. If you dont keep the water moving and let it stagnate too much you will definitely still get low o2 pockets and root rot. I had tried pushing high o2 through a flood and drain table instead of flood and drain, eventualy the root mass created problems and root rot took over. This took a long time to fail however and when I switch back to healthy flow the plants bounced back. The Nano Bubbles when high enough killed or stopped the root rot.

grass_fish, do you have any information you can share about your design? I'm currently talking to a company from china making these. Its about 2000usd for a system with an oxygen concentrator.

grass_fish said:

So far the benefits from observation with no real scientific method is 20-30% increase in yield.

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Sorry, I just cant believe that. Im ok with you believing non-scientific theories about DO and CO2 in water, but if that kind of increase in yield was even remotely possible, the big guys would be all over it in a flash.

Seriously, that would be major big news in agribusiness.

fancythat said:

grass_fish, do you have any information you can share about your design? I'm currently talking to a company from china making these. Its about 2000usd for a system with an oxygen concentrator.

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You really should check the science behind that before you part with your $$.

fancythat said:

Its about 2000usd for a system with an oxygen concentrator.

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yikes! i can buy a O2 concentrator used off craigslist for $200

rkymtnman said:

yikes! i can buy a O2 concentrator used off craigslist for $200

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It's not just an o2 concentrator. The quote from the company is 650USD for a 3 liter/min oxygen concentrator, the micro bubbler is 1700.

Larry3215 said:

Sorry, I just cant believe that. Im ok with you believing non-scientific theories about DO and CO2 in water, but if that kind of increase in yield was even remotely possible, the big guys would be all over it in a flash.

Seriously, that would be major big news in agribusiness.



You really should check the science behind that before you part with your $$.

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I've done enough due diligence to be willing to try this out. One of the thing I did was take a simple 3 day aquaponics class at lethbridge college. most of the content was for beginners but there were some extremely experienced doc's and profs teaching the class, and sharing some very interesting things. Anyways, their hydroponics system was rdwc in beds about 4' wide, 20' long 8-12" deep. Floating styrofoam trays. NO AIRSTONES in the water, it seamed insane to pretty much observe extremely healthy plants with roots growing in stangnant water. There was some current but pretty low current for the volume of water. The yield of the produce and the health of the roots was unbelievable. Their d.o. levels were above saturation levels. So after seeing their system, I am interested in trying it out.

"non-scientific theories" is a pretty bold statement. In fact, as a side note, when I was talking to one of the professors about why some of their findings aren't aren't 'textbook' he said that there are still so many parameters, some of which are even beyond their realm of understanding at this point, to simply deem it fact. eg. at a government facility in edmonton they were growing lettuce, (i dont know why) they had not checked the ph or ec for quite a while, when a visiting doc checked the ph and ec, the ph was very low, i believe around 4-5 and the ec was around 4. Long story short, they found a new bacteria that had never been known, but was able to solubilize the nutrients. Just saying, non-scientific theories don't really mean jack.

fancythat said:

It's not just an o2 concentrator. The quote from the company is 650USD for a 3 liter/min oxygen concentrator, the micro bubbler is 1700

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have you asked for references from commercial growers that use their system?

rkymtnman said:

have you asked for references from commercial growers that use their system?

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I haven't

fancythat said:

I haven't

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i would before i spend 2 grand.