Calcium Reactor

[ponokareefer]

After doing a lot of research, I've decided that a calcium reactor would probably be in my tanks best interests. I have a 125 gallon mixed reef, and was wondering what type would work best for my system? There seems to be quite a few models out there, and I was wondering if they all operate outside of the tank, or if any operate inside a sump? The reason I ask, is all seem to be of a significant size and I would have to do a little cramming to get it to fit. Also, it seems like you need to be able to get bottled CO2. Where do you find this item?

Ryan