MarinePure

Getting my tank cycled and I am considering adding some Marine Pure to my overflow (Marineland Corner flow 120 G). A little more background, have about 60 lbs of Reef Saver dry rock (much less porous than conventional live rock) and bare bottom with tan colored HDPE (no false sandbed- too much work, looks pretty good actually!) So, I fee like I need more surface area for biologic filtration so was going to put one block in sump and thinking about another one cut in pieces to make removal/maintenance easier into the bottom of my overflow chamber. I theorize that the flow will be low and therefore likely more anoxic in the bottom of overflow than elsewhere and might get more N2 production.

Thoughts?