Keep the bubbles - lose the stones!

GreenMan<3 said:

I think you're assumption is wrong. As a hardcore freshwater aquarist, tank water oxygen level is of extreme importance. I would say that there is probably very little difference in surface agitation when using a stone or no stone. In theory, the smaller bubbles of the stone create greater surface area for O2 dissolution, but you are right that very little O2 is dissolved from the bubbles, most is from surface agitation.

My thought, and experience (though not scientifically measured), is that a mass of tiny bubbles bursting on the surface creates more oxygen exchange than a couple of large, wavy bubbles. Yes, no stone probably does create more actually agitation of the surface as measured by actual water movement, but in terms of surface area available for oxygen exchange the mass of bubbles should be superior.

I also inject carbon dioxide into my planted aquariums, and within that area there is much experimentation and study done around bubble size and injection method vs. dissolution rate, with the goal being to get 100% of your CO2 to dissolve in the water (as opposed to bubbling away at the surface). The CO2 issue isn't relevant to hydro, I only mention it to say that I have had experience with many inexpensive DIY and store bought methods to dissolve gas in water.

At the end of the day, for the purposes of hydroponics (increasing oxygen to the roots via increasing oxygen in the nut solution) I don't believe that there would be a significant impact on plant growth rate or production if you are using the same air pump with or without an airstone. That being said, I'd love to see someone actually do a pseudo-scientific study and get a definitive answer. Personally, I think there are so many other variables, many of which are tough if not impossible to control, that affect a plants growth and yield that it would be virtually impossible even for the most advanced hydro gardener to come up with a definitive answer outside of a laboratory setting.

Personally, I have a fairly shallow reservoir and use an old, 6 inch aquarium airstone that I had laying around. I chose that one simply because it was laying around and not of much use for me in my aquariums. Had that not been available, I probably would have used a standard aquarium airstone. For the curious, there are dozens of types of airstones of various sizes and various bubble production sizes.

Now the confession - this is my first hydro grow. I've been a soil grower for years and have really dug into the science of hydro. But, although my hydro experience doesn't qualify me to speak to the results of nut aeration, I think my freshwater aquatics experience certainly might lend some insight into how to get oxygen into a liquid reservoir.

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cannatari said:

Let me explain why air-stones are a waste of money and actually impair the oxygenation of your reservoir solution.

Fact: Water is oxygenated buy the movement of it's surface, not by little bubbles within.

Although the tiny bubbles produced by an air-stone do agitate the surface of your res water, if you pull the air-stone off of your hose, the hose alone will produce much larger bubbles that agitate the surface much better. Your nutrient solution will ripple like a lake and oxygenate your water the same way nature does.

I don't hear of anybody using this method, maybe I'm the first. I'd like to hear comments from anybody who is up for the challenge. If this is old news I apologize. Just thought I'd give back.

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GreenMan<3 said:

I think you're assumption is wrong. What? As a hardcore freshwater aquarist, tank water oxygen level is of extreme importance. If you overstock your tank, yes it is. I keep and propogate marine SPS corals. The hardest corals to keep so I have a bit of knowledge of aquarium residents DO needs. I would say that there is probably very little difference in surface agitation when using a stone or no stone. Wrong again. Not using a stone will nearly always provide more surface agitation. In theory, the smaller bubbles of the stone create greater surface area for O2 dissolution, but you are right that very little O2 is dissolved from the bubbles, No you are wrong again. Very little O2 is dissolved from large bubbles in compariosn to small bubbles. most is from surface agitation. That depends on the area of the water air interface. (Actual open surface area) and the amount of agitation of the surface. If the area of all the under water small bubble's surfaces are larger than the air water interface then the bubbles will supply more DO, especaiily when the bubbles get caught up in the water current where they have long contact times so as to give up a high percentage of their O2 gas. The bubbles often adhere to roots and below the surface reservoir walls etc and give up almost their entire concentration of O2.

My thought, and experience (though not scientifically measured), is that a mass of tiny bubbles bursting on the surface creates more oxygen exchange than a couple of large, wavy bubbles. No,that is not true in a real sense. I even use DO meters rather than just assuming something. (Your a "hardcore freshwater aquarist" without a DO meter. Strange.) The water surface that is turbulent due to the currents caused by the large bubbles rapid floatation to the surface causes a greater input of DO then the bubbles supply DO. I think perahaps you are confusing CO exchange at the surface for O2 water DO saturation at atmospheric pressure. Yes, no stone probably does create more actually agitation of the surface as measured by actual water movement, (Actually small bubbles cause more water currents then large bubbles but they produce less surface agitation. Many smallbubbles acusemore water to be lifted to the surfacethen a few larger bubbles.) but in terms of surface area available for oxygen exchange the mass of bubbles should be superior. No as only a small portion of the bubbles are in contact with the water when at at the waters surface. Then they burst losing all remaining O2 without any more exchange taking place.

I also inject carbon dioxide into my planted aquariums, and within that area there is much experimentation and study done around bubble size and injection method vs. dissolution rate, (the studies have been competed for decades) with the goal being to get 100% of your CO2 to dissolve in the water (as opposed to bubbling away at the surface) (There are likely no new studies going on in that areea, there is an acute lack of knowledge by aqurists in that area though.). The CO2 issue isn't relevant to hydro, I only mention it to say that I have had experience with many inexpensive DIY and store bought methods to dissolve gas in water. There in lies a major problem, inexpensive DIY. If you actually wish to learn something let me know, as your view points (opinions) are backwards. But I only get paid to design water treatment and sewage treatment plants and their aeration su ystems as well as teach teach graduate and Doctoral candidate students to do the same.

At the end of the day, for the purposes of hydroponics (increasing oxygen to the roots via increasing oxygen in the nut solution) I don't believe that there would be a significant impact on plant growth rate or production if you are using the same air pump with or without an airstone. That being said, I'd love to see someone actually do a pseudo-scientific study and get a definitive answer. Personally, I think there are so many other variables, many of which are tough if not impossible to control, that affect a plants growth and yield that it would be virtually impossible even for the most advanced hydro gardener to come up with a definitive answer outside of a laboratory setting.

The studies have already been done. The pronblem is not a need for lower reservoir temps and higher DO levels from cooler temps and aeration. The problem is getting enough eater still containing DI O inconatact with the root masses inner roots. It does not matter how high the DO is if the water is not contacting the roots that need the DO. DWC sytems with very high corculation rates do not need low temp reservoir or high DO. Roots do not need contact with water at levels above 2 ppm. As long as you keep the water contacting all roots at 2 ppm or higher prior to the contact all is well. This does not happen though with most NTF, small tube aero or the average DWC systems.

Personally, I have a fairly shallow reservoir and use an old, 6 inch aquarium airstone that I had laying around. I chose that one simply because it was laying around and not of much use for me in my aquariums. Had that not been available, I probably would have used a standard aquarium airstone. For the curious, there are dozens of types of airstones of various sizes and various bubble production sizes. Your point?

Now the confession - this is my first hydro grow. Really. I've been a soil grower for years and have really dug into the science of hydro. But, although my hydro experience doesn't qualify me to speak to the results of nut aeration, I think my freshwater aquatics experience certainly might lend some insight into how to get oxygen into a liquid reservoir. No as your beliefs are incorrect and obviously not founded in science or any measured emperical data.

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http://en.wikipedia.org/wiki/Water_aeration#Water_quality said:

Dissolved oxygen (DO) is a major contributor to water quality. Not only do fish and other aquatic animals need it, but oxygen breathing aerobic bacteria decompose organic matter. Pond bottoms of organic soils demand larger amounts of oxygen. When oxygen concentrations become low, anoxic conditions may develop which can decrease the pond's ability to support life.

Aeration speeds up this process of oxidizing organic and mineral pollution. In fact, if there is sufficient aeration, the fish will be able to survive, where before they suddenly died. By pumping compressed air out to the bottom of a pond or lake with the use of a diffuser, the rising air bubbles and the friction caused in the water will bring bottom water to the surface where it is exposed to the atmosphere. Large volumes of water thus release noxious gases to the atmosphere, water picks up oxygen while circulating at the surface.

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xum said:

Now to my understanding, this is saying that surface aeration will oxygenate the surface only, possibly leaving the bottom of the pond, lake, or reservoir in an anoxic state. So long as you're moving the water from the bottom of the reservoir, lake, or pond in some way, you're oxygenating the water. Whether it be from an airstone, a diffuser, or an airline with holes cut in it. Granted, pushing a lot more air from the bottom will speed the oxygenation process up.

Now the real debate here is really, "How much air do you need to move through your reservoir to properly oxygenate the water?"

Luckily for us, each box the airpumps come in have ratings for how many gallons they are suitable for! Dude what a bull shit thing to say. What makes you think those figures are based upon DO levels, or DO replenishntt or even circulatory rates. As far as anyone know sthose numbers were pulled out of the manfacturers babie's diaper. Get Real Dude. At best they are based upon some myth thatfor each gllon of water a tank contains it will support 2 inches of fish body length and some scientist at sometimein history nade some stupid generalized statement that same 2 inch long fish need a ceratin amount of Do and they pooped out some suggested coefficient that would indicate how much Do the silly pumps can add to the water wwith an avergae unrestricted air flow. Lame suggestion! And, if you're lucky enough to own one you can use a dissolved oxygen meter to test your water's oxygenation. And likely you will never see much change in a moderate size reservoir, unless you stuck the probe inside the centera of a good sized root mass. You would likely with most DWC resrvoirs find thar the DO in the center of the roots mass is below 2 ppm if not zero or near zero. You would find the same results sticking a DO probein the centert of the water logged massesof roots laying in the bottom of small aerop tubes or NTF root masses. I have a shelf and box of DO meters. I have a real nice home made one that has a probe that is only 1/8 inches in diameter. IE it is simple to check in the cennter of the mass with a small tipped probe with little affect on the DO from roots being pushed aside.

The only benefit I see about millions of tiny bubbles coming from the bottom of the reservoir from multiple airstones is the bubbles will pop and splash water up to hit the roots that aren't submerged in the water so they don't dry out. WHAT? They have the potential to appreciably increase the DO if it is below saturation levels Dude. That is sufficient reason for their ecommendation, as they can do so even when there is little water surface area for oxygen to enter thewater. Duh. But I swear roots dangling in the water act like a wick and draw the water up, but what do I know? And justwaht does that have to dow ith anything do ith this discussion Dude. .

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hydroboy27 said:

i love when scientific minds say "no" and simple minds observe obvious gains. No it simply means we base things on science rather than often unfounded opinions like typically used by a layman.

9 times out of 10, the scientific mind will argue tooth and toe nail, but then, they get all nice, when they see the gains, and then they take the time AFTER the dispute to look for an ADDITIONAL scientific principle that explains observable reality. What? Are you trying to say your creating miracles and that we are stumped and amazed by these miracles and try to fit science to these "miracles." Not likely behavior from a scientist Dude.


For those of you using high volume/velocity air in dwc or the doubleD drip buckets systems. There are likely almost NO growers doing this in proportion to those not using these methods so your argument is moot. This is about simple common DWC using common methodologies not roots blowers or Sweet water Blowers etc. the reason you see the successes that you do is not just oxygen. It is also the REMOVAL OF C02. What removal of CO2?Just as there is DO in the water, there is c02 in the water, and too much of it is toxic to the roots. There has to be excessive CO2 in the room air or in the air pumped into the reservoir for this to be an issue.

While water may only need a level 2 of DO as mentioned above, rates of change, and rates of absorbtion by the roots is key. Duh, this scientist ist has written about that repeatedly. For any grower that has done dwc, with water not moving at all, and just a tiny air stone, VS a grower who keeps their water moving (few DWC growers do this), and might introduce larger bubbles from a non air stone hose, they know that the agitation that gets new fresh water in and around the roots, makes great beneficial There are a very small minority of DWC growers using enough circulation as need to assure all roots receive adequate DO. They are the ones that typically run DWC system interconnected. They use many pumps, and many air stones and they work well but consume huge amounts of power. I have only seen one DWC of that caliper show up in this forum and it was by a link to another forum.

Putting a big air pump, outside the room and pumping large quantities of fresh 02 rich air into the res that the roots are hanging in is a great benefit, especially when the room has high co2 levels being induced, and is air tight... No it provides no additional help with a CO2 issue with a air tight CO2 supplemented grow room.

Think about this. IF no new air from outside the room is introduced into the res where the roots hang, then how is the c02 air that naturally occurs in a root chamber over time, let alone the c02 that is being added to the room.... how is any of this going to be removed from the water. It will NOT. It will reach a level proportional to the room CO2 concentration and stay at that levels. It will cause all v calcium and magnesium to be used as buffers in bicarbonate compounds, Duh! Your Point?

Any o2 rich air being added to the water, (pump outside the room) will leach away the c02 as it bubbles to the surface. No it will not. The more the merrier. And since TOO MUCH AIR CANT HURT THE ROOTS... i see absolutely no point in any argument AGAINST adding additional air to a res or chamber. Waste of energy and the fact that the air your pumping in might be actually increasing the amount of CO2 in the water. All it can do is help, plus it pressurizes the chamber (what kind of air pump are you suggesting people use?). or res if it has a lid on it, which then keeps the c02 added to the room, from re-entering the res or chamber, as quickly, (doubtfully, likely a negligible difference with a lid that s full of holes where if putting enough air through them would kill the plant roots if trying for a positive pressure) especially if your res or chamber is nearly air tight (again with that absurdity). I say nearly because air can always escape past the plants trunk however you have it suspended in the chamber. DUh, the disclaimer that throws out merely all you wrote.

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hydroboy27 said:

the degasser principle applies to adding large quantities of o2 rich air to a chamber or res (What are you talking about Dude. Aeration in a reservoir (adding large quantities of air) is no where near as efficient as a degassing column at stripping excessive CO2 or other gasses from a solution as a degassing column), just not as efficient You are definitely mixed up. Do I need to draw pictures or explain further. If you want to remove excess CO2 from a reservoir in a grow room already containing high concentrations of CO2 about the only way to so so is to send the water outside the room and stripped the think simple physics: concentrations wish to equalize therefore concentrations that are high move toward the low concentrations not the other way around as you suggest. That means doing it out side the grow room. Simple as that. The simplest way to do that is by gas stripping and the easiest and most efficient way to do so is with a gas stripping column. But what do I know I just have degrees that providing me with the knowledge needed to design water treatment plants and I teach graduate students and supervise doctorate candidates in their research work and documentation for their dessertation. People who think in absolutes instead of gray, cant understand that there is some degassing going on WITHIN THE ROOT BALL Your being funny again right? when large amounts of o2 rich air are injected to a dwc system NOT CO2 yes, DO no. What is your thing about being back wards here Dude?

And the people who have degassers, get egos, "What" . No they just get systems that work properly. (if you want to swap insults you know I am very good at that and your posts have left lots of thinks for me to use as a base of throwing insults. I would not suggest you continue in that manner though, Dude. and say, if you cant afford a ferrari, why even bother trying to go fast? You a funny Child, Ha Ha. I can likely afford to buy anything I desire Child. Same principle. Degasser is better <AND CHEAP TO BUILD CHILD> (Yes because it will work, your suggestion would not. work to remove excessive CO2 and the "degasser" it will also keep the water fully saturated with DO).... but to say a degasser is an important part, and then to turn around and say adding o2 rich air to a root ball is pointless... Dude I have never said or implied that. Are you really trying to say I have or just as usual grasping at straws? I said it makes no difference if the water has a slightly higher DO if that water never comes into contact with the center of the root mass hanging in the water to allow uptake of the DO laden water.

Roots up take oxygen by taking up nutrient water containing DO. mj roots do not inhale or exhale O2 gas Dude.

well, thats like saying theres no point in going fast unless you have a ferrari logo on your hood. Huh! Grasping at straws again child?

o2 rich air degasses water... period. Under some conditions. Under some cons conditions it does not degas at all. Anything is better than nothing. Anything means something. However your method would provide nothing (IE not anything) as far as CO2 degassing is concerned in the situation you presented Dude. Its a world of gray. (No usually it is not. Here there are clear defined areas of black and white.) This is why the "idiots" observe time and time again that adding lots of 02 rich air to a root ball area, shows beneficial signs. Dude every time you get s desperate you get broad and general again. <"adding lots of air"> Are you saying bunches of people are using lots of air in their DEWC's. I think you are quite wrong. There are few DWC growers using adequate enough volumes of air in proper enough ways in their average DWC systems to prevent root rot or to maximize growth. Perghaps yourconfusing a liitle better performance as being much motre than a l=ittle better than theprec vious horrible.

That has nothing to do with Degassing usually and that is what the degassing column is about. The fact that it greatly increases the DO even better more efficiently than it can be done in the reservoir is just a second benefit.

Yes pumping air into the water can move the roots around (but seldom does that happen in the typical DWC reservoir) so that more water as saturated with DO makes it to the inner roots. Yes it can introduce DO under some conditions but seldom with a DWC, unless you have just a few plants so there is a large open water surafce area, or you are using many, many, very, very small bubbles. But with small bubbles you would then also need a circulation pumps to keep the roots moving so water with DO can get to the root masses inner roots. I explained at I believe twice Dude. The efficient way to handle both is to use a needle wheel pump with a venturi or a submersible pump with a venturi valve. I also explained that. You have just jabbered and made many ludicrous statements. They have created an in-efficient de-gasser, (No Dude it is not going to happen.) If the room has low CO2 and the reservoir has low CO2 and you pump air into the water that has high CO2 you will increase the CO2 in the reservoir (this is what happens with a poorly ventilated grow room without CO2 supplementation as it has CO2 lower than air outside the room where the air pump is located). A "de-gasser" that does not de-gas is not inefficient it is a non "de-gasser: Dude.

If they are supplementing CO2 they are not degassing of CO2 by blowing lower CO2 laden air through the water in the Grow room because the room has high CO so no degassing will take place. Is there something about that you can not understand? and they think its the extra o2 that the plant is using, when its both that and the removal of c02, as well as agitation of the roots, and oxidizing principles that keep root rot from setting in.

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KeegoSmalls said:

OK if you thought like a pothead instead of all scientific, you would realize that airstones increase oxygen in the water because it increases the surface area of air in the bubbles (more bubbles = more air to water contact). No, your kidding right? What does thinking like a pot head mean? Do you mean just passing on myths and nonsence and good ole boy bull*hit or acting or actualy being ignorant. If so I think your confusing the overly vocal minority of that type as being like a "pot head." Not all pot heads are couch locked high school drop outs. I know many pot heads that have a thirst for growing knowledge with sound scientific backing more than regurgitated myths and bull*hit as is commonly spread asds gosg pel in the groing forums and by marketers.

Thats why they use them in the fish tanks. Also they use C02 in the water to help plants, so going to pump my co2 in the water when I go aero!! Wow, that would not be a very good idea, unless you do not want any calcium or magnesium to be avilable to your plants. Your comparing an underwater palnts needs to Mj plant needs. I guess you plan on continuing buy most of your mj.

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DivinePower said:

Fatman - I really love it when people argue with you. It makes me giggle!

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plumsmooth said:

Has anyone witnessed more arguing? then on Cannabis Cultivation boards? Even more than Politics! IS someone going to correct my grammar...

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cannatari said:

Let me explain why air-stones are a waste of money and actually impair the oxygenation of your reservoir solution.

Fact: Water is oxygenated buy the movement of it's surface, not by little bubbles within.

Although the tiny bubbles produced by an air-stone do agitate the surface of your res water, if you pull the air-stone off of your hose, the hose alone will produce much larger bubbles that agitate the surface much better. Your nutrient solution will ripple like a lake and oxygenate your water the same way nature does.

I don't hear of anybody using this method, maybe I'm the first. I'd like to hear comments from anybody who is up for the challenge. If this is old news I apologize. Just thought I'd give back.

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cannatari said:

Let me explain why air-stones are a waste of money and actually impair the oxygenation of your reservoir solution.

Fact: Water is oxygenated buy the movement of it's surface, not by little bubbles within.

Although the tiny bubbles produced by an air-stone do agitate the surface of your res water, if you pull the air-stone off of your hose, the hose alone will produce much larger bubbles that agitate the surface much better. Your nutrient solution will ripple like a lake and oxygenate your water the same way nature does.

I don't hear of anybody using this method, maybe I'm the first. I'd like to hear comments from anybody who is up for the challenge. If this is old news I apologize. Just thought I'd give back.

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