# DIY CO2 reactor.



## ForestDave (10 Apr 2021)

I previously had been taking  @Magoo  “Anybody use this Chinese External CO2 reactor” but thought I should start a new post.

I am sure there are much quicker ways to skin a cat but I have at last fitted my DIY CO2 reactor. I set it up yesterday and am really happy with it. It’s pretty much silent apart from a little bit of quiet gurgling in the first 30-60mins. If I put my ear next to it I can hear things going on but you would struggle to notice it much. I managed a 0.9ph drop in 2.5 hrs on a 200L tank and it’s bottomed out there so I’ve just turned the CO2 up a smidge. The tank water is crystal clear without a bubble in sight, (Unfortunately this shows up even more of the of tiny uninvited random snails! 🙄).

The Venturi isn’t working yet. I will shorten the Venturi pipe in the reactor tomorrow and see if that helps. It also has an internal Venturi for any gas which gets trapped around the outside of the cone cylinder. I put a purge valve before the inlet pipe at the top as I reasoned that as the reactor was an inverted cone inside any trapped air would bubble up the pipe. Tbh I used it for a tiny bit of gas yesterday when setting up but it seemed to clear itself although it was louder for the first 30mins or so yesterday.

All in all, it was a bit of fun and kept me entertained. I had to keep fighting the thought, "why on earth didn’t I just adapt a 2ltr coke bottle or some other bottle shape," but once I realized the original flat-topped cylinder design wasn’t working for various reasons (see other thread), it made sense to keep playing around with what I had in front of me.
My tank waters clear though and it’s quiet. Thanks to @Hanuman and @Zeus. for the much-appreciated tips!


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## ForestDave (10 Apr 2021)

Here’s a shot of it in place under the tank.


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## ForestDave (10 Apr 2021)

Here’s an idea of the dimensions  from earlier images before I laminated some fibreglass sheet on it.


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## Zeus. (10 Apr 2021)

I've had a recent idea to fine tune a CO2 reactor, '3D printing' to get your bespoke parts/fittings made. If it works and you can get the parts made at a reasonable price, the only limit is your imagination, will save all those pipes fittings ,jubilee clips, drilling and gluing. Bespoke top and bottom and clear pipe/tube in middle


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## ForestDave (10 Apr 2021)

Zeus. said:


> I've had a recent idea to fine tune a CO2 reactor, '3D printing' to get your bespoke parts/fittings made. If it works and you can get the parts made at a reasonable price, the only limit is your imagination, will save all those pipes fittings ,jubilee clips, drilling and gluing. Bespoke top and bottom and clear pipe/tube in middle


Haha! What would I do with myself!? 
No seriously that sounds like a great idea. I have a mate who made  a replacement part for his Shimano bike gear lever on a £200 Amazon 3D printer. They’re brilliant machines.
I would say that the condensing cone at the top seems to work a treat though.


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## Hanuman (15 Sep 2021)

@ForestDave How has your cone shaped reactor been doing?


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## ForestDave (16 Sep 2021)

Hanuman said:


> @ForestDave How has your cone shaped reactor been doing?


Hi Hanuman. 
My cone construction wasn't up to scratch and the water got under the fiberglass wrap. I swapped it out for an 18mm foam disk with a slight inward bevel directing the gas towards the water inlet pipe. I had some teething problems as I was getting a noisy filter pump due to air getting in there. It turned out that I'd over tightened the cheap purge/air valve and air was being drawn in and building up in the filter as I had fractured the valve. I blocked the purge valve  off completely and I don't seem to need it. There's a short bubble build up at start up of CO2 then it quietens down.  The 18mm disc in the reactor pretty much get's all the CO2 disolved. There is the odd little bubble which I am not sure whether they are O2 or CO2. Either way it's pretty good but slightly noisier than the cone. I ran out of steam on the venturi but may have another bash if I get the time. I'll probably make a mark 2 cone as well! I was going to get a mate to spin up one on a lathe to use as a mould.
Cheers 
Dave.


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## Hanuman (16 Sep 2021)

I did a cone version of my initial design and so far I don't see the need of a venturi anymore. It seems to be dissolving CO2 pretty efficienciently


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