Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I allow the sponges to rest on the bottom, and loose media is in nylon stockings, not loose in the sump. Those bags are also on the floor of the sump.
I do find there is a lot of debris that settles down there, so when I clean the sponges that bottom edge is the worst, and I need to vacuum the sump really well.