IUnknown;10471 said:
Tom wrote:
"The only way to add more than 100% ambient levels is through plant production."
What about injecting O2?
Well yea, but I'm the only person that seems to have done so to date.
Going back about 4 years ago.
I still have to read most of the other threads on this subject but was curious as to the conclusion of the "Co2 actaully being O2 bubbles" issue.
Well I can tell you this much, they are wrong unless the bubbles rise up from the plant. O2 would have to cross that boundary layer, much like the slowed rate of diffusion from the surface layer intereface.
You know..........just like why the gas exchange rate is 10,000 times slower in liquid and air? That goes out the window when these same folks want to argue in favor of O2. CO23 will go into solution fast, but not one of these folks shows how CO2 and O2 goes _out of solution_ and into a gas phase.
That is key since they claim that the gas in the bubble changes rapidly.
they claim it changes from CO2 in a few seconds (some suggest instenanous!) to O2 or N2 gas.
But it takes time for the gas to come out of solution and into the microbubble.
As that time passes, the area, the boundary layer around a apheron will have a higher level of CO2 than the water adjacent to it.
That's the other part they have not considered.
A micro pH probe could show this.
I might be able to get one at the lab.
It seems like the best way to disprove that would be to run the diffusser in a tank without plants (maybe this was done?). If the DO meter measures an increase in Oxygen levels then this would show that the Co2 bubbles are actually being filled up by O2 as the Co2 diffusses out. The idea is that the Co2 bubbles would be sucking Oxygen from the surface of the tank to over saturate the tank(were else would the O2 come from?). This would explain why the bubbles persist more later in the day as the tank is saturated with O2.
I've run diffusers in tanks without plants, I was studying algae growth responses to CO2 and O2 at elevated levels.
I don't think there is enough O2 removal to detect anything significant if this occurs, which I don't think it is.
The other issue that I'm not convinced about is 30ppm being saturated enough to slow down the rate of diffussion. This thread did a pretty good job of disproving that idea,
"CO2 Solubility Experiment - Photos, Video.....Evidence! " . I guess you could connect a ph meter to a computer to see if the absorption rate changes at all. If it doesn't the Co2 would be a line in a ph vs time chart. It would be a bell curve if 30 ppm slowed down the saturation rate.
But the video shows
nothing about what the gas is actually.
you andf everyone esle that's kept plants over the years have seen the increase time the CO2 microbubbles persist later in the day, these are not from plants, you can place the CO2 ADA diffuser right out in front, have the current blasting the mist around and see this over and over again.
The video does not address the microbubble, it does address the CO2 in a reactor tube which is a different case.
I've got a difusser in the mail to see how things improve. Regardless of whats actually happening the extra O2 is good for feeding bacteria, etc. Interesting stuff, I'm glad you have a thick enough skin to deal with all the attacks Tom, the hobby would not be going anywhere otherwise.
There's a simple thing, I know they are wrong, so I don't care as long as the attacks are not personal.
I'm not particularly certain what the gas is yet in the reactor tubes as they build up over time, but I can find out what it is made up of.
Thing is, no one esle will ever do that.
I ask folks to, but they are more interested in arguing Tom Barr is wrong than actually engauging in doing any work. At least Ted did some work and put it up on the web.
Which is a lot more than I can say for others.
I have some other thing I haver tio do and finish up before I can get to that question just yet, but for now, a simple DO meter and the treatement/control will tell you if the plants grow faster or not with the method.
I'm not so sure about Ted's trail either.
I want to go back and make very sure this is actually the case.
I tested O2 in the reactor tubes much like Ted did for CO2 and O2 does not dissolve anywhere near the same rate, O2 and N2 are very insoluble in water.
These are the two best candidates for the other gases.
Ted did not test O2, I did.
So that's one gas in the reactor tubes we can rule out.
I have N2 at work, so I can test that one also but it's very insoluble and we can predict the rate it dissolves.
Now what about knocking N2 and O2 out of solution?
This is different than getting them to dissolve.
Reactors, unlike diffuser stones, have what precisely?
Generally they have a place for the bubbles to degas.
They have those bioball media which are designed for high flow degassing. This degases and then reabsorbs again.
But............I also see the gas form in my internal CO2 reactors which have no such degassing media of any sort.
The large bubble forms daily.
With or without the venturi running also.
The gas is purged also due to the burp holes in the side.
So it's not all build up like in the in line versions.
Why would the gas in a solution degas there and not else where?
There is a lot of unknowns so far and the results from the O2 meter suggest there is something to this and we can watch those microbubbles, folks can speculate that they are no longer CO2, but not one of those folks will ever get around to showing it is or is not with any certainly.
I cannot say that O2 will dissolve that fast into a microbubble, nor N2.
CO2 does dissolve much faster than either of these gases. It has to go across a gas/liquid boundary layer to do so, same with CO2.
So I cannot see how these rates can be the same, we can watch the micro bubbles come right out of the disc that we know is 100% CO2 and they don't disappear.
Apparently when the shoe is on the other foot....now they do not respond........funny how that works.
Regards,
Tom Barr