Hey.. stupid question... I know sand adds to the denitrification process but just curious if you needed the live sand in the refugium with the cheto.. or will it thrive without it... just curious...... because Im thinking that my sump for right now is out of the question I am going to put a HOB reffugium on my tank because of the plumbing issues. what exacly is the refugium mud other than being nutrient rich.... do any of you use it. go with the one with protein skimmer or without.. (skifish already know your answer on this lol as I am already doing 20% weekly water changes.) anyways.... just curious on thoughts