Custom CO2 Reactor

[3es]

Hi Everyone,

I've researched and read about the many different ways of insuring CO2 to efficiently mix with the water and am planning on creating an external reactor. The design I've come up with obviously has similarities with many DIY reactors (such as the one mentioned in the Sticky) but of course includes my own unique way of setting it up. From what I've read, the design should work but would always like to hear other's opinions on the actual setup.The picture below illustrates how I was planning to construct the reactor.



I already have all the parts from a previous tank and I could easily set it up as illustrated above. But before proceeding with the actual build would like any feedback on it. Pros, cons, anything would be helpful. If anything in the picture isn't clear, let me know. Thanks

Toshi

[BFG]

My humble opinion is that I personally believe that the usage of bio-ball are really not necessary. We here in SG have a diy external co2 reactor made from a water filtration device. I will try to find a pic or maybe a fellow member here might link it. You could follow the design. Pretty efficient, without the bio-ball.

[bossteck]

Hi,

Here's what I foresee, the bio balls will not do anything, they will not spin and will not in any way help in getting the co2 dissolved.

If it is really sealed properly, you will probably see co2 gas collecting at the top of your reactor. If not, you will see bubbles escaping from the hole where your co2 tube enters the reactor.

You will probably be better off shifting your co2 inlet nearer to the inlet (which you labelled 'From Water Pump') the water pressure will force the co2 bubbles against the bio balls and help (a little) break them into smaller sized bubbles. But still, if your bubble rate is high, you will most likely still see the situation I mentioned above.

[3es]

My humble opinion is that I personally believe that the usage of bio-ball are really not necessary. We here in SG have a diy external co2 reactor made from a water filtration device. I will try to find a pic or maybe a fellow member here might link it. You could follow the design. Pretty efficient, without the bio-ball.

Thanks for your comments and input BFG.

I would love to check out what you guys use to create a reactor. Hopefully someone can post a link to it

Toshi

[Goondoo]

Thanks for your comments and input BFG.

I would love to check out what you guys use to create a reactor. Hopefully someone can post a link to it

Toshi

I will get you some pictures since mine had not been in used.... maybe you check back later.

[3es]

Hi,

Here's what I foresee, the bio balls will not do anything, they will not spin and will not in any way help in getting the co2 dissolved.

If it is really sealed properly, you will probably see co2 gas collecting at the top of your reactor. If not, you will see bubbles escaping from the hole where your co2 tube enters the reactor.

You will probably be better off shifting your co2 inlet nearer to the inlet (which you labelled 'From Water Pump') the water pressure will force the co2 bubbles against the bio balls and help (a little) break them into smaller sized bubbles. But still, if your bubble rate is high, you will most likely still see the situation I mentioned above.

Hi bossteck, thanks for your input on the efficiency of the setup!

From the illustration, I can see where it may seem that the bio-balls would not move and aid in the break-up of the CO2 bubbles. The container is actually an old protein skimmer and in the past when it was in use, the water within the container would create a vortex effect. I felt that if I added some bio-balls, they would move about within this vortex and help break up (slightly) the CO2 bubbles.

In either case, your insight on how the bubbles will accumulate at the top of the reactor has made me rethink the design slighty. Below is an illustration of the modified design with your advice in use.



By inverting the container, I could ensure that any CO2 bubbles accumulating at the top are easily sucked through the powerhead and distributed throughout the tank. As advised, bio-balls have been removed and the CO2 inlet moved closer to the water input into the container.

Thanks again for your input

Toshi

[3es]

I will get you some pictures since mine had not been in used.... maybe you check back later.

Thank you Goondoo, appreciate it!

[Goondoo]

I will get you some pictures since mine had not been in used.... maybe you check back later.

Here you are.... don't mind the picture quality please















Hope this helps.......

[3es]

Here you are.... don't mind the picture quality please

[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010081.jpg[/IMG]


[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010076.jpg[/IMG]


[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010074.jpg[/IMG]


[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010073.jpg[/IMG]


[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010078.jpg[/IMG]

Hope this helps.......

Hi Billy, thank you for sharing the photos. Could you do a quick explanation on the flow of this setup?

[Goondoo]

Hi Billy, thank you for sharing the photos. Could you do a quick explanation on the flow of this setup?

Basically, after you connect it up, you will need to invert the callister while the filter is on as shown in the picture to force out air




When water is filled invert back....

CO2 is introduced from a drilled hole with a connector at the base of the callister. The water entered the valve, spray into the callister with a spiral effect and mixed with the CO2 thats rising up and exit from the base... (refer to the lousy art work attached)

[3es]

Basically, after you connect it up, you will need to invert the callister while the filter is on as shown in the picture to force out air

[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010078c.jpg[/IMG]


When water is filled invert back....

CO2 is introduced from a drilled hole with a connector at the base of the callister. The water entered the valve, spray into the callister with a spiral effect and mixed with the CO2 thats rising up and exit from the base... (refer to the lousy art work attached)

[/IMG]http://img.photobucket.com/albums/v140/Goondoo/testing/P1010078b.jpg[/IMG]

Great! Thanks for the explanation. That's pretty much how I intend to set it up, with the vortex effect and all. I could probably use the first design I posted (but without bio-balls) and just relocate the CO2 inlet near the water pump inlet. It should work similarly After thinking a bit more about it, the second design may not work if a vortex is created since the powerhead most likely wouldn't receive a constant flow of water at the top.

Thanks again Billy, appreciate it.

Toshi

[PeterGwee]

The main thing of a reactor is to keep the CO2 in it as long as you can to fully dissolve the gas. As the CO2/O2 builds up, the bioballs helps in creating extra surfaces for gas exchange in the sealed compartment. Without the bioballs (they don't need to spin to work), the area of contact becomes one large flat surface instead of multiple surfaces which bioballs can create. (More surface area of contact, more efficient.)

You can consider the mist CO2 idea since its direct pure CO2 gas contact with the plant stomata instead of dissolved aquaeous CO2. All you need is just a limewood airstone, diffuser or powerhead to do it.

Regards
Peter Gwee

[3es]

The main thing of a reactor is to keep the CO2 in it as long as you can to fully dissolve the gas. As the CO2/O2 builds up, the bioballs helps in creating extra surfaces for gas exchange in the sealed compartment. Without the bioballs (they don't need to spin to work), the area of contact becomes one large flat surface instead of multiple surfaces which bioballs can create. (More surface area of contact, more efficient.)

You can consider the mist CO2 idea since its direct pure CO2 gas contact with the plant stomata instead of dissolved aquaeous CO2. All you need is just a limewood airstone, diffuser or powerhead to do it.

Regards
Peter Gwee

Hi Peter, thanks for the clarification on the bio-balls.

In my designs illustrated above, I did originally figure that the bio-balls in contact with the CO2 bubbles would help a little in the break down and contact ime of the bubbles. Then even further break up of the bubbles would be accomplished through the powerhead which should ultimately create tiny CO2 bubbles distributed throughout the tank. Do you feel this reasoning is correct?

Or if I chose a mist effect method with a powerhead, I could setup just a CO2 inlet tube right before the intake of a powerhead which then shoots the water into the tank. Would this be just as (or more) effective as my proposed design?

Just to clarify my filtration setup, I'm using a trickle filter setup. So if I were to do the latter setup, I would place the powerhead within the sump.

As always, any input is greatly appreciated and thanks for your advice and time!

Toshi

[bossteck]

If you leave one spoonful of condense milk long enough in your black coffee, it will eventually dissolve. But stirring would definitely help hasten the process. The same is true when it comes to dissolving co2 isn't it?

The issue of bio ball providing more surface for gas exchange is true only if they manage to trap some co2 bubbles among them. But i am sure there are more efficient means of doing this.

The reason why many found the external reactor shown in the photo effective is probably due to its large volumn and the fact that the outlet is situated at the bottom. Much like 3es's first design. The co2 gas will be trapped at the top, vortex generated will provide the stirring effect. There is no need to provide the extra surface simply because there is no way for the co2 to escape.

3es, I wouldn't do your design #2 because what will probably happen is that the powerhead will draw out any undissolved co2 bubbles.

Stick to your first design, but instead of drilling the hole for the co2 tude at the top of your old skimmer, do it like what you have in your second design, ie, feed in from the bottom, that way, you'll be sure to have a sealed container at the top and no co2 gas will escape. the vortex effect of your skimmer will take care of things and you can be sure that all co2 will eventually dissolve.

Just my opinion.

[3es]

If you leave one spoonful of condense milk long enough in your black coffee, it will eventually dissolve. But stirring would definitely help hasten the process. The same is true when it comes to dissolving co2 isn't it?

The issue of bio ball providing more surface for gas exchange is true only if they manage to trap some co2 bubbles among them. But i am sure there are more efficient means of doing this.

The reason why many found the external reactor shown in the photo effective is probably due to its large volumn and the fact that the outlet is situated at the bottom. Much like 3es's first design. The co2 gas will be trapped at the top, vortex generated will provide the stirring effect. There is no need to provide the extra surface simply because there is no way for the co2 to escape.

3es, I wouldn't do your design #2 because what will probably happen is that the powerhead will draw out any undissolved co2 bubbles.

Stick to your first design, but instead of drilling the hole for the co2 tude at the top of your old skimmer, do it like what you have in your second design, ie, feed in from the bottom, that way, you'll be sure to have a sealed container at the top and no co2 gas will escape. the vortex effect of your skimmer will take care of things and you can be sure that all co2 will eventually dissolve.

Just my opinion.

Bossteck,
That makes good sense, thanks for the explanation. As you mentioned, I think I'll use the first design with the relocated CO2 inlet tube.

If anyone else has something to add, please do so as it's always good to hear other opinions and ideas.

Toshi

[solonavi]

Pardon me for getting OT.

I will like to ask all those of u using external reactor similar to this type posted. When the CO2 build up at the top of the reactor, do u see that those build up CO2 getting dissolved eventually? Cos (correct me if I'm wrong), by design, when the CO2 build up, it will push the water level down. Since the water level gets lower and lower, how is it possible that those CO2 on the top will be dissolve into the water?

Need some advice.

Thanks
JC

[3es]

Pardon me for getting OT.

I will like to ask all those of u using external reactor similar to this type posted. When the CO2 build up at the top of the reactor, do u see that those build up CO2 getting dissolved eventually? Cos (correct me if I'm wrong), by design, when the CO2 build up, it will push the water level down. Since the water level gets lower and lower, how is it possible that those CO2 on the top will be dissolve into the water?

Need some advice.

Thanks
JC

Hi JC,

In my understanding of this type of external reactor, there is a vortex created inside. This vortex creates a spiral of water going straight down. Therefore, the CO2 bubbles should go up, get caught in the vortex, then travel back down through it causing it to mix efficiently with the water before being output to the tank. Just my 2 cents.

Toshi

[neon]

That design is good when you have a good flowrate minimum of 1000L / h, else yes , the Co2 will eventually push down.

This filter container reactor was my very first reactor, but I found it so so only ! I found the c02 misting method (power head suck in CO2, chop the co2 into hundreds of tiny tiny bubbles , spray out thru rainbar place at the lower back of the tank work best, and O2 saturation/concentration reach the "bubbling effect" within the short time, ie 1 hour or so.

[BFG]

Here is my explanation, part of how I figure the thing works.

The water exiting from the tube in the reactor itself will force the water in the reactor to spin. The force will push the water in 1 direction, doesn't matter which way but the water will continue to spin in the reactor. I do not believe a vortex will occur as the area where a vortex appeared is currently occupied by the tube in the reactor.

When you introduced or supply co2 into the reactor, it will float to the water surface. Continuous supply of the co2 will cause a pocket of air ( co2 ) above the water line in the reactor as the air has no where else to go ( at this moment ). Since the co2 is being supplied continuously, the amount will increase until you would see a gap being formed at the top of the reactor. This area contained the accumulated co2.

How the co2 get into the water.
Because of the continuous supply of water, the water itself will find it's way out from the reactor. But the exit out of the reactor is not an easy path. The exit is located way at the bottom of the reactor. This will cause a slight hindrance for the water to exit. This hindrance may cause a slight pressure built up in the reactor. This slight pressure built up is the key ingredient to the success of the reactor. When the amount of water increases, it will try to move in anywhere it could. The exit will only let an amount of water out depending on the pump used. So as the water rises, it will automatically push it's volume onto the pocket of air. Once the pressure built up reaches a certain amount, the co2 will be absorbed into the body of water. This happens continuously as long as the co2 supply is being fed, with the pump feeding water into the reactor. Since the water can absorb only so much of co2 at a time, the undissolved co2 will still form at the top of the reactor, ready to be dissolved again when the next volume of water is being fed into the reactor.

This is why I figure that the bio ball has no use in the reactor. The only place where co2 and water merged is at the water surface in the reactor where the co2 pocket bubble is formed. The co2 is not being absorbed at anywhere else but only in this area. The built up of the volume of co2 and the amount of water coming into the reactor will force each other to merged into a mixture of co2 enriched water.

This is my personal believe. Honestly, I could be wrong as I am not an expert but a fellow hobbyist who enjoy this hobby very much.

[BFG]

How to tell if your External Co2 Reactor is working.

The External Co2 reactor is an equipment where water and co2 merged. Since we were told that co2 plays an important part in preventing algae growth, most of us would have increase the supply of co2. I did that too and feed more co2 now than when I was 1st starting out. But how do you tell if it works and works properly?

When you use it, you will notice that there will be a pocket of air ( co2 ) at the top part of the reactor. This is normal. To know if the reactor works is when the co2 supply is shut off. Gradually, when the co2 supply is cut-off, the water will continuously absorbed the co2. Why? Remember that the water itself is being pumped into the reactor and the increasing volume of water will go anywhere where it can move and the next to the exit of the reactor, the co2 bubble is the next logical place. Co2 is less dense than water and it could be easily absorbed into the water volume. This will happen. After a few minutes or hour depending, you will have only a container of water. The co2 will be fully absorbed.

But if you find that your reactor is half-filled or nearly full of air before the co2 supply is being introduced, I believe you have a air-leak somewhere in your hose joint. It did happen to me. What made me look into the problem is when my pump made a slight noise when an air bubble hit the impeller. For months on end, I thought this was normal. But the urge to make my setup as quiet as possible prompted me to look into the matter. I traced the flow of bubble to a joint where I'd seen the small bubble forming at the joint connecting the hose to my pump. I switch off the pump, pull off the hose and cut-off the old hose edge where it made a connection to the joint. The new hose edge was trimmed so that it was a nice levelled cut, not one where it made a tapered edge. I push back the hose fully into the connection and started the pump. It did work till now. No more air leak into the canister filter. So if you have a air leak occuring, remove the hose, recut it's edge and make sure you cut it levelled, not tapered. And then insert it fully into the connection.

Hope this helps! Just sharing my experience.