I heard people/read that people who use fine sand in aquariums use sponges for the intakes to help prevent the fine sand from getting into the filter. Now I don't have any fine sand in my aquariums, but that is what I have heard/read.
This is what I think you are looking for.
I have also read that sponge filter store beninfical bacteria. So if you ever need to setup a hospital tank, just pop one of those off the intake and place it on the intake in the hostpital tank, and you got beninfical bacteria to help out also.