Proposed Co2 Reactor

[aibcarpentry]

So yet another DIY CO2 reactor.................only this one is going to be made 'properly'

By that I mean acrylic will be cut using a CNC machine and assembled by someone who makes the likes of fluidised media reactors etc for marines.

I've had a bit of a chat with him and I'm very interested to hear other peoples thoughts on what I'm asking for, if anything doesn't make sense please ask.

-100mm cylinder. (4")
-sat on plinth approx 100mm high.
-overall reactor height 600m (2') (including plinth) maybe a little shorter.
-flow enters through top and exits through bottom.
-CO2 injected through pushfit connection in lid and will have acrylic tube connected inside cylinder I can then adjust the height at which the CO2 is injected; I'm working on the best way to try and centralise this in the centre of the flow as I thought this might help.
-second pushfit connection in lid I can use in a multiple of ways but mainly to bleed air. Could be used for some kind of loop if it proves too much gas gets trapped in the top unsure until I try it but someone might know.
-use 1/2" bulkhead type fittings with 1/2" BSP thread top and bottom meaning I can chop and change to what fittings I want with ease as I plan to hard plumb some of it.
-Removable grill in bottom to keep bioballs from clogging exit and enable cleaning
-Option to fill with bio balls to help dissolve CO2 (I plan to use them)

Unsure what I've missed but I'm sure something but as I say please give me your honest input.

Considered a venturi but I want flow from my filter to run through so hopefully things will work without.

Pictures just to give you an idea but ignore the 90's top and bottom.

Cheers
Andrew

 

[Kyalgae]

Did you see this thread? https://barrreport.com/threads/amazon-17-ft-planted-aquarium.14344/

On this huge tank they use a gas contactor cone.

There’s an example of one.

Apparently this is as good as it gets according to Tom. I think what matters when you build one of these cones is the speed of the water that comes in the top. If you had a DC pump you could change this easily. If you had to slow flow the bubbles won’t get broken up like you see in the video. I realize you probably can’t make a cone, but you could make a pyramidal cone. Tom linked this site as commercial examples of this type of gas contactor. http://pentairaes.com/oxygen-ozone-contact-cones-50-psi.html pretty expensive, and probably too large for a regular sized tank. It would be pretty cool to see something like that.

 

[aibcarpentry]

Did you see this thread? https://barrreport.com/threads/amazon-17-ft-planted-aquarium.14344/

On this huge tank they use a gas contactor cone.

There’s an example of one.

Apparently this is as good as it gets according to Tom. I think what matters when you build one of these cones is the speed of the water that comes in the top. If you had a DC pump you could change this easily. If you had to slow flow the bubbles won’t get broken up like you see in the video. I realize you probably can’t make a cone, but you could make a pyramidal cone. Tom linked this site as commercial examples of this type of gas contactor. http://pentairaes.com/oxygen-ozone-contact-cones-50-psi.html pretty expensive, and probably too large for a regular sized tank. It would be pretty cool to see something like that.

I imagine the price is as good as it comes also! Haha.
I'm not even sure people really manufacture acrylic in this way that much in the UK so that would make it even harder.
As much as I'd love to try this I think it's just too far out of reality.

Any input for the more likely reactor or are they now 'rubbished'?

 

[a1matt]

What size tank is it for?

 

[aibcarpentry]

What size tank is it for?

I have a 100l and a 200l which I might put 2 on just to spread it around a bit more evenly.

 

[a1matt]

Considered a venturi but I want flow from my filter to run through so hopefully things will work without.

It sounds like you consider having a venturi and using the reactor inline to be mutually exclusive, if so, why is that?

 

[aibcarpentry]

It sounds like you consider having a venturi and using the reactor inline to be mutually exclusive, if so, why is that?

I think; infact I'd go as far say I know the venturi would restrict the flow too much running it inline. It would be like trying to run the flow through something like a 6mm pipe instead of the normal 16.

Do you disagree?

 

[VaughnH]

My first impression is that you are overthinking this. I did that when I made my first CO2 diffuser, and I was very unhappy with it. A simple and effective way to build this is with PVC pipe and the fittings that are used with PVC. Another simple, and effective design is made using a water filter housing. I suggest searching this forum for threads about building those types of reactors.

 

[aibcarpentry]

My first impression is that you are overthinking this. I did that when I made my first CO2 diffuser, and I was very unhappy with it. A simple and effective way to build this is with PVC pipe and the fittings that are used with PVC. Another simple, and effective design is made using a water filter housing. I suggest searching this forum for threads about building those types of reactors.

Thanks for the input.
I'm trying not to overthink things but I'd like it to work too.
What made you unhappy with yours?
By the time I've purchased the pieces needed in the UK I can have one made from acrylic and it be much more robust.
I really need the flow to enter the top and exit the bottom due to space and that's another reason I've avoided the DIY ones made from a filter housing.

 

[a1matt]

I think; infact I'd go as far say I know the venturi would restrict the flow too much running it inline. It would be like trying to run the flow through something like a 6mm pipe instead of the normal 16.

Do you disagree?

I dont understand fluid dynamics enough to agree or disagree!

My understanding, which could be totally wrong, is that if the venturi is a loop design (as opposed to the 'choke' style), it won't divert enough flow from the main pipe to prohibit driving the reactor inline with an external filter.

I always saw the same problem from the other perspective... will the filter provide enough flow to activate the venturi, or will the loop just sit there inactive.

I'm curious to know the opinions of those with experiential knowledge.

My other thought on venturi loops, is that any reduction in flow is a trade off against the loss of flow that you would get without it if your reactor fills with gas.

At the end of the day, as long as your reactor is physically large enough you will be good. I think it really is that simple.

 

[aibcarpentry]

I dont understand fluid dynamics enough to agree or disagree!

I'm referring to the 'choke' style of venturi.

I simply don't understand the loop design so I'm all ears for anyone that can explain how this could work for me without putting the loop back in before the filter.
From what I think I understand it relies upon the suction which I don't know how I could get without putting the loop in before the filter.
I know I'm not the only one to not understand things so hopefully someone will come along and explain.

 

[VaughnH]

Thanks for the input.
I'm trying not to overthink things but I'd like it to work too.
What made you unhappy with yours?
By the time I've purchased the pieces needed in the UK I can have one made from acrylic and it be much more robust.
I really need the flow to enter the top and exit the bottom due to space and that's another reason I've avoided the DIY ones made from a filter housing.

I had mine glued together, all acrylic, so when it needed some maintenance I couldn't do it. I also used an airstone in the CO2 line to get small bubbles of CO2, and that disintegrated in about a year. I was/am a retired engineer, so I had a very good time designing it, but the results weren't what I expected.

The "Cerges" reactor is a home water system, all house filter housing, used with no filter element in it, with the incoming flow going from top down to the bottom, as I recall. https://barrreport.com/articles/how-to-build-a-cerges-co2-reactor.43/ Every thing I can remember reading about it was good. I made one a few years ago, but never did have a tank that needed it, so I scrapped it. It was very easy to make.

 

[aibcarpentry]

I had mine glued together, all acrylic, so when it needed some maintenance I couldn't do it

The lid will be removable so I can get in to clean things, top/bottom connectors will be screw type fittings and the grill in the bottom will be removable so I can get in to clean things, that's what would make it very expensive to build one myself as I don't want to build one and seal it up then being unable to clean things at a later date.

I also used an airstone in the CO2 line to get small bubbles of CO2, and that disintegrated in about a year

Was it an airstone intended for CO2?

I have the problem where I am quite restricted with space underneath both in height and footprint so by having the proposed reactor it actually helps me as I can take the feed out of the bottom and run it straight back up putting a heater inline whereas it's a bit tight if I don't do this. The Cerges style reactors don't allow for this.

 

[VaughnH]

The airstone I used on mine was just an ordinary one - at that time I was much too "green" to know the difference. It will be very interesting to see how well this one works, so keep us up-to-date on it, please.