I have the Carib-Sea Hawaiian Black sand in my tank and I love it. Gives a different look compared to the light sands/substrates that seem to be the more popular choice. I haven't noticed any ill-effects even with magnetic glass scrapers. I have been curious about a sand sifting type fish but do not have one and at the moment have no intentions of adding one. I have a sea cucumber and hermit crabs and snails that seem to do a fine job of turning over the sand bed.