If you have a sump it's more efficient to simply port the gas directly into the return chamber that has the pump.
I'm not really familiar with the calcium reactor but doesn't it drip feed the calcium carbonate solution into the sump?
Drip feeding into the sump will not be useful. I assume you propose to use it without the calcium media?
In any case, whatever configuration you are thinking of would be much less efficient than simply porting gas directly into the sump.
Cheers,