If the sand was shallow, it should be fine to reuse. If it was more than a inch or so deep, Ithink I'd feel better using new sand.
The new water in and of itself isn't a problem, as long as the
SG, temp,
pH, etc match, jst like a waterchange. The best you can do is get he rock, sand and livestock into ther new quarters and keep a VERY close eye on
ammonia,
nitrite over the next couple of weeks. If they start climbing, you"ll have to combat them with water changes.
Sorry to hear about the tank, that sucks....
