I've got a 170G with a smallish sump (came with the tank). It's probably about 30G with the w/d section full of bioballs. I'm planning to add the fx5 to take care of mech mainly but I was planning to at least use some of the baskets for bio. Any media suggestions? I was thinking some combo of regular floss and either biomax or ehfisubstrat but I'd love to hear others' opinions.