One other thing I would add to the list that ccCapt mentioned is computer control. When you start messing with c02 and CA
you really need to be able to monitor your pH 24/7 and have function to stop dosing if need be. A CA
reactor is not something to just add on a whim it is one of those additions that require several other components to function properly.
With that said I will soon be adding one to my system. I have mostly SPS
corals in my tank as well as a frag tank packed full of SPS
. I can't keep up with the demand and dosing is becoming expensive.