Nano CO2 Scrubber

ReefSharkBuilder · Oct 15, 2020

Ok everyone, I know that you all may think this is a bit over engineered. However, I have been going nuts trying to get my ph up but I have a desktop tank and I do not have the space for a huge BRS reactor or the like so I set out to build a nano CO2 Reactor.

I started with a reactor that I found on Amazon as my base.
Some 1/4" (6mm) OD sturdy airline tubing
Some sponges
and some push-connect fittings for RODI lines
I already had the IceCap K1-nano skimmer on my tank

totaling out to about $40 USD.

The reactor fits perfectly into an Innovative Marine reactor clamp used for their desktop in-tank equipment. So this is how I mounted it to the side of my tank.

I decided to design a recirculating scrubber so that I had an additional amount of control other than turning the skimmer on or off. This is what the push connectors are for. Out of the package that I ordered I only needed the "T" fitting and the ball valve. The reactor comes with push connect fittings for RODI lines so I didn't have to bother with it.
I started by cutting generous amounts of the airline tubing to fit the space I have.

I used clear airline so that I could easily observe if there was excessive moisture in the line that could potentially melt the media inside of the reactor and cause a lot of problems. I also positioned the "T" fitting in the way that I did in order to allow a small slump in the airline, thus preventing any water from directly going into the reactor chamber and allowing for not only an outside air intake, but a quick let-off valve if I notice any liquid in the line.

the line that does NOT attach to the ball valve will go into the skimmer cap. I had to widen the hole a slight amount for the airline to fit snugly into the cap with minimal gaps.

Now, there is the concern that bubbles will form at the mouth of the air intake inside of the skimmer lid and cause excessive moisture in the lines and in the chamber. To prevent this, I took one of the sponges and cut it up into small chunks about 1.5cm x 1.5cm. I then took an knife and poked a hole half way through one side so that the airline can fit into the hole and be covered after being inserted into the skimmer cap.

After this there was the touchy bit of how to get the airline to attach to the skimmer muffler. The IceCap doesn't have a piped intake like most skimmer mufflers do. So, I designed one to be 3D printed that you can download here. You should not need to modify the file at all. Other than adding supports for your particular brand of printer. I printed this on my resin printer the Creality LD-002R. Since this part will not be in water, I am not concerned with toxicity or leeching into the tank (although, I don't think that would be an issue anyways if it is properly cured)
This model was designed to fit into the stock intake tubing that goes between the venturi attachment and the muffler. So there shouldn't be any modification to your skimmer at all. The trick to this muffler is the intake pipe. The inside diameter of the intake pipe is 6mm (1/4") to snugly fit the airline tubing. This will allow for easy disassembly during maintenance, changing media, etc.

While that was printing I took the top off of the reactor and put it face down on top of one of the sponges and cut it to size to fit in the bottom of the reactor. Most CO2 media doesn't work as efficiently, or at all, if there is a lack of a small amount of moisture. This sponge will be a great way to prevent the media from melting and causing problems while still maintaining a small amount of moisture in the reaction chamber. The sponge also is an extra barrier to the thin filter provided with the reactor.

After the print on the muffler finishes I will continue the post!

Lasse · Oct 17, 2020

Thank you for sharing

Sincerely Lasse

ReefSharkBuilder · Oct 31, 2020

Ok after putting a few things together and some sand paper and creative thinking. I was able to get the CO2 scrubber to function properly. I now have the pH up from 7.4 before the scrubber was installed. Now it is consistently reading between 8.2-8.4 all day long.

First things first, The muffler worked wonderfully until I saw that the intake portion of the tube had shrunk just enough to prevent the airline from being pushed inside of it. I will be updating the .stl file on Thingiverse to compensate for this. But for the time being I decided to get some heat-shrink tubing and use it to link the intake portion of the muffler and the airline. This has performed wonderfully well with an air-tight seal.

The next portion of the build went really well, except for one thing...
The airline pulling the CO2 dense air out of the skimmer cup chamber was perfectly fit. however, there isn't a good enough seal around the edges to keep the cap on with the weight of the airline tugging on it. So my temporary solution was to place a small limestone rock on top as a counterweight. I will do more development on this as I have more free time. Getting that fit is important to allow for maximum CO2 elimination.

Hanging the CO2 scrubbing media went well while using the IM reactor mount. Not much to be said here, except that I am really happy with the quality of the reactor chamber and with the media I purchased from BRS.

Next I want to make an important portion known. When CO2 scrubbing media gets too wet it begins to decompose and release harmful toxins into the tank through the airlines. This can quickly take down an entire tank. Therefore I have included a small simple solution to this problem. Just like we use drip loops to prevent an electrical fire, I have employed the same concept so that excess moisture can not reach the reaction chamber easily at all. This simple dip in the line that pulls from the skimmer cup and feeds into the reaction chamber serves multiple purposes.
1) It prevents a skimmer overflow situation from being a disaster and buys time to fix it.
2) In the case that too much moisture collects in the airline, the same ball valve I would use to lower the pH if it ever gets too high, will be used to drain the collected moisture.
3) as stated above, it is valve used for a recirculating scrubber setup to adjust the pH if it gets too high or too low.