My 40 gal. long sump/refuge is up and running. Skimmer has a lot of bubbling happening. Now, I want to apply the phosban reactors (2) that I got. My tank is 125 gal. FOWLR right now. Is it necessary to install 2 phosban reactors? My main question is do I put the pump for the reactor in the skimmer portion of the sump or return area of sump or refugium?