With my move and new tank I will be completely replacing my old sand except for a cup or two to help populate the new bed. Seems I should know by now but I am not sure which sand I want to purchase. I used a regualr sand before and was happy with it at first. Then it started to develop nasty cyano on it and I had to siphon out so much and replace with some more. With time it always looked dirty and the largwer particle sizes and many shell and rock pieces make it look terrible. My wife always wanted a uniform sized white sand bed. What about oolitic sand or sugar grain?? I hear a lot of people say it blows around a lot but others say once it settles it is fine. With a 25inch tall tank I can position my powerheads high enough to hopefully not blow it all around. I plan on only having a 1-2inch sandbed for now.