Question about calcium reactors?

[Eurogurl]

I am setting up a 120g system, 75g display and about 50g in the sump. I have never used a calcium reactor before, and have been doing some research, but I am a little unclear on how they actually work.

I was looking at this one for my system

Deltec PF501

I understand that you put the calcium medium into the chamber and it pumps water through therefor adding calcium to the system and keeping it at desired lvls. But what is the CO2 for? And what does the bubble counter do that they talk about?

Not really sure I understand this part very well? Can anyone help a girl out? Or point me in the right direction of where I need to be reading?

I wanted to set up a full blown reef tank, this would be my first one, I have only had FOWLR's before. But definetly interested in keeping corals and invertabrates in this new tank!

 

[cham]

If your setting up a softie system then IMHO you don't need one. I personally would do a Kalkwasser ATO, or dose if you can't do that.

If your going for LPS & SPS sytem then here is some good reading for you.

http://www.reefkeeping.com/issues/2002-05/sh/feature/index.php

Basically, the idea behind the CO2 is to lower the PH of the water in the reaction chamber low enough to have the media start to dissolve into the tank water. The bubble counter helps keep track of how much C02 your adding to the system so you can dial it in.