Why do you need a BIG Calcium Reactor?

[urbor]

Ok so im looking into the geo calcium reactor lineup. I have never had a calcium reactor, so im kind of new to them. I just set up a 500 gallon display reef about 650 total. It will be mostly SPS. I want to get a calcium reactor but I'm a little confused on why I would need a 8x18 vs a 6x18. Is the only difference that you would just need to fill it up with media more often to keep up with your tanks demands??


Thanks
tom

 

[nyvp]

correct as you get larger calcium loads only dif is how often you will need to refill it.