Question about sand.

[RichKlit]

Hello first time posting here but been lurking for awhile, great site! Im thinking about getting into the hobby and would like a small biocube type reef tank. There is a 12 gallon available with live rock, some corals, crabs, and snails etc. My question is once i pick it up and move it i would have to drain the water etc would i be ok to add sand as currently the tank has none and i really want a sand bed. Will it have negative effects or am i all clear?