So considering my recent discovery that I was pumping the waste water from my RO into my tank for top off, I am considering modifying a phosban reactor to house polyfilter. I was just thinking I would cut them into circles with holes in the center to force the water through them and stack them in a phosban reactor. The way my sump is set up it doesn't lend itself to using them any other way I can think of. What do you guys think?