I personally don't have any but I was wondering how much BB is stored in the substrate compared to media? I moving in about 2 months and am going to remove my substrate (play sand) and was thinking about just leaving it out for ease of cleaning since I will have an oscar and pleco in the tank which are very messy and produce alot of waste. I do like the more natural look, but I was just wondering who has bare bottoms or other views on them. Thanks!