External CO2 Reactor using Fluidized Reactor

[solonavi]

Hi Guys,

Been doing some thinking and read the two sticking and some post in the net on diy CO2 reactor in preparation for my next planted tank.

As I used to keep marine thus was thinking of using the Fluidized Reactor to act as external CO2 Reactor. Did a simple drawing on it. My main concern is at the U tube where the tank water is fed into the reactor. Will CO2 be accumulating at the U tube or maybe with enough flow it will not be an issue.



Any advice or comments?

Thanks
JC

[solonavi]

This the FR I'll be using.



If I need more water reaction time to diffuse the CO2 into the water, I can even extend it by add an extension.



This is how it looks like. (note that the reactor is filled with marine media, Rowa & Carbon)



Cheers
JC

[sevo88]

I tried this on the smaller fluidized reactor. It did not work out because undissolved CO2 would collect in the bioballs, form large bubbles and escape ultimately through the outlet. With your FR, is it possible to reverse the water inlet and outlet? It was not possible in mine because it was a commercial one with a floating ball as a one way valve to prevent sand getting into pump. If you can reverse the water flow, the FR will be the same as the other common CO2 external reactors.

[solonavi]

Its possible to reverse the inlet and outlet but I think the flow rate will be affected.

Mind me asking, since your encounter is due to undissolved CO2 collecting in the bioballs which den form large bubbles and escape through the outlet. Isn't all other CO2 reactor uses bio-ball?

I was hoping that if there are any undissolved CO2 after the bioballs, they will be collected at the tp sponge and as water flow through them, it gets dissolved eventually.

JC

[sevo88]

Undissolved CO2 will collect in the sponge and bioballs to form large gas bubbles and pockets, escaping through the outlet. When the flow is reversed, any undissolved gas will collect in the bioballs or be trapped at the top until they are dissolved. When the flow is too slow, trapped gas may collect all the way down to the outlet pipe. Some external CO2 reactors provide a switch for de-gassing.

[solonavi]

Thanks for the explaination. Wat is the recommended flow rate in the reactor?

I have redo my drawing.



Cheers
JC

[tawauboy]

if the reactor is big enough to accomodate a ceramic diffuser, why not insert one. co2 coming out of the ceramic diffuser will be smaller and this should help with the co2 diffusion rate.

[BFG]

Solonavi, I would like to add a suggestion. I'm referring to the latest pic that you have posted.

1) I believe the use of the bio-ball are not necessary.
2) The pipe from the canister output. If you can add an 'L' piece of pvc pipe from this ( where the sponge is ) this will encourage the water to spin. The top sponge is not needed there as that area will be occupied by co2 gas that will accumulate naturally.
3) The pipe inside the reactor. I think you do not need the length that you have drawn. Cut around a 1/3 of it away if you so desire. The remaining pipe in that reactor, you could drill multiple hole but not all the length of the pipe. Just drill those holes about half of the bottom pipe length.
4) The bottom sponge is not needed also.

Or another idea. Seeing from your actual FR pics. The one with your hand on it.

1) You have to turn the unit upside down.
2) The pipe with the pvc in the reactor will be the input from the canister filter. The other pipe will be the outlet.

The 2nd recommendation is simpler and better but you need to rig up something to hold the unit while it is upside down permanently. An idea that I have is to find a large pvc pipe section that is the size of the reactor width. You could cut away slot for the 2 pipes going in and out of the reactor.

Hope my explanation is clear.

[solonavi]

if the reactor is big enough to accomodate a ceramic diffuser, why not insert one. co2 coming out of the ceramic diffuser will be smaller and this should help with the co2 diffusion rate.

Thanks for the suggestion. Actually inside the reactor has something similar to a ceramic diffuser, basically its a circular acrylic with multiple 5mm holes.

Any idea where I can find those ceramic diffuser u mentioned?

Thanks
JC

[solonavi]

Solonavi, I would like to add a suggestion. I'm referring to the latest pic that you have posted.

1) I believe the use of the bio-ball are not necessary.
2) The pipe from the canister output. If you can add an 'L' piece of pvc pipe from this ( where the sponge is ) this will encourage the water to spin. The top sponge is not needed there as that area will be occupied by co2 gas that will accumulate naturally.
3) The pipe inside the reactor. I think you do not need the length that you have drawn. Cut around a 1/3 of it away if you so desire. The remaining pipe in that reactor, you could drill multiple hole but not all the length of the pipe. Just drill those holes about half of the bottom pipe length.
4) The bottom sponge is not needed also.

- Tot bio-ball helps diffusing the CO2? No?
- Can't add a 'L' joint because as I mentioned earlier, its connected to a acrylic with multiple holes.
- Wun having more space for teh tank water to mix witht he CO2 allows better diffusing?
Another problem that I face is not modifying too much on this reactor in case I will go back to my marine.

Or another idea. Seeing from your actual FR pics. The one with your hand on it.

1) You have to turn the unit upside down.
2) The pipe with the pvc in the reactor will be the input from the canister filter. The other pipe will be the outlet.

The 2nd recommendation is simpler and better but you need to rig up something to hold the unit while it is upside down permanently. An idea that I have is to find a large pvc pipe section that is the size of the reactor width. You could cut away slot for the 2 pipes going in and out of the reactor.

Hope my explanation is clear.

I like this idea much better. Save alot of effort and simple to do. Will try this out den.


Thanks alot for all the suggestions and advise.

Cheers
JC

[BFG]

Solonavi, do post a pic afterward. Might help the other members here too!

[solonavi]

Hope I've got this right.



Cheers
JC

[tawauboy]

Thanks for the suggestion. Actually inside the reactor has something similar to a ceramic diffuser, basically its a circular acrylic with multiple 5mm holes.

Any idea where I can find those ceramic diffuser u mentioned?

Thanks
JC

you can these ceramic diffuser from any decent lfs. just look for a glass device with built-in white plate and a 'u' shaped glass tube connected to it. the ceramic plate has tiny pores and c02 forced out of this plate will be tiny (<0.5mm diameter).

and from your latest drawing, i would
i) remove the top acrylic with multiple 5mm holes
ii) add a tube to direct water to outer edges
this will make the water spin inside the reactor and helps with co2 diffusion.

[BFG]

I agree. If you can remove the 2 plates, it's better. On the edge of the pipe in the reactor, add an 'L' piece of pipe. This will help to push the water to spin in the reactor. There's no need for the bio-ball. It will only slow down the water movement in the reactor. You do not need to worry about the co2 not mixing with the water. The pressure ( not much though ) will make the co2 to be easily absorbed naturally.

[solonavi]

I can remove the top plate and add a 90degree PVC joint but not the bottom due to the bottom area is a fixed structure. If I will remove the plate, It will make better sense to juz do a new reactor from scratch.

I've modified the diagram to add teh 90degree joint.


Cheers
JC

[tawauboy]

extend the tube so that the 90 degree bend is right at the top. looking good.
make sure that you check for leaks before you hook it up.

[michael lai]

Hi Solonavi,
My 2 cents, why in heaven's name would you wanna built something that big? I'm constantly trying to remove any unsightly or unneccesary items from the tank. Less tubing, less powerheads Etc....an internal reactor is quite cheap and extremely efficient if you 'tweak' it.
I'm not trying to pour cold water man, but I think your efforts would be well spent on other areas.

Peace.

[solonavi]

Hi michael_lai, thanks for the pointers. As I mentioned earlier, this is a FR I have from my marine tank, thus all I want is to do as little modifications as possible to convert it into a CO2 reactor. If too much effort is needed, I'll juz drop the idea.

Gd news is that so far, there are only a few simple modifications needed which imho is no sweat.
1) Invert the reactor
2) Remove one of the plate and add a 'L' joint
3) Remove the sponge at the top
4) Add a 'T' joint to inject in CO2

Cheers
JC

[sevo88]

Hi, Solonavi,
I think you latest design should work well for you.
I am a fan of external co2 reactor because it does not occupy any space inside the tank. Its performance is efficient and consistent.
The internal CO2 diffuser with a ceramic disc is in my opinion a hazzle. It collects algae within 1-2 weeks. Not only sightly, the algae also impairs the preformance of the diffuser. The larger CO2 bubbles flow straight to the water surface and are lost to atmosphere.

[solonavi]

Thanks sevo88 for the encouragement.

Will post any updates on this project when available. Meantime, if anyone has any suggestions or comments, keep them coming.

Cheers
JC