I run 2 Rena XP3's with mostly mech media in them. I also have a good skimmer on there and 2 SEIO 1200 pumps for circulation(very important). As for sand, about 2" but the fish move it around all the time. Also, it is not the fine sand as the pumps would move that around too much. I plan on adding another 50lbs of LR to the 50 already in there.
HTH
