okay, an HOB is a filter that hangs on the back.
you dont want media in the filter because it can trap detritus, and become a nitrate trap.
yea. you want to stay away from mechanical filtration in SW, especially reefs, bra.
this is why we have nitrogen cycles and DSB, and LR. this allows our tanks to PROCESS waste, not just take out.
filterpads, bio-balls, acrylic chucks, are all trash. wothless.
maybe keep some carbon around for chemical removal and such. but if your having clarity problems, you r lookin at like an algae/bacteria bloom, precipitation event, etc.
a filter pad will be like a band-aid on a bullet wound