How does everyone feel about external co2 reactors? I'm not trying to make a vs. thread, just wondering if there are any major trade offs.

I was really hooked on the diffusers because I like to see the bubbles and have read some pros here about misting, but I constantly break the glass ones; limewood diffusers work great, but they need cleaning often and seem to start letting out larger and less bubbles - Especially right when I don't have to time to clean it.

I'd like to build a DIY external reactor in hopes that I can have low maintenance, consistent diffusion, but I enjoy the pearling.

Right now I'm looking at my tank, and all things co2 being equal, I'm seeing 1/3 of the bubbles floating across the tank that I normally have. A water change and a limewood cleaning would fix this, but todays not the day, and I fear that this may be a big player in my algae problems. I suppose going a whole photoperiod with poor diffusion makes for a bad tank day on a 10gal.

Also, I really don't have room for a venturi in my 10gal if anyone is going in that direction.

No opinions?

10 gal tank is a bit too small for the other options.
Such as a External DIY reactor, they are fine and work well etc.
Maybe a little one.

TOM's has a small little canister that might work well for running an External one on a small tank also.
Try a plastic Azoo diffuser if you are breaking them.


Regards,
Tom Barr

thanks Tom, I didn't know a 10gal was too small for an external reactor. :-)

After some reading last night, I went ahead and built a reactor. Simple one out of PVC, no bio balls or anything, and connected it on the return flow. The only difference is I couldn't find any plugs, but instead had to use threaded inserts and caps where a plug was required. I had read that a larger diameter was better for total diffusion and there where thoughts about a smaller one actually promoting micro bubbles, so I went with 1 1/2" diameter. I tried to go shorter, but somehow I still managed to build it about 22" tall.

It's been functioning on my tank for a little over 3 hours as I post this, and so far I'm pleased. The same volume of CO2 is being placed into the system, my ph is about the same, but I have lots of of tiny bubbles! And since I was able to direct my filter return flow into the tank so to speak instead of at the diffusor, I can now blow those bubbles clear across the tank.

During the first hour or so, the bubbles where of larger size and from what I read probably made up alot of air bubbles. But now the bubbles are smaller than any of the diffusers I have used. I used to be able to sit 15' away and see the bubbles, now I have to be up close to the tank to see them.

Plants are pearling the same or better than before the reactor, plus, everything is covered in bubbles. I'm not going to say yet that it's ALL pearling. If I loose the tiny bubbles as things settle in, I will build another reactor smaller in size, as I still want to follow the micro bubble theory. I'm also noticing some speedy growth ona couple of fast growers, like when I first set everything up.

I know I probably didn't give diffusors enough of a chance, but if this works well... I like it.

But so far so good!

You can use it, but a 22" tallr eactor for a 10 gal is a bit over kill

Regards,
Tom Barr

co2 mist? a stone and a powerhead is pretty inconspicuous.

I didn't plan on making it 22" long, I just threw it together quick. Will it cause any problems? I don't think I'm seeing the relationship between the length of the reactor and tank size.