well that's not really true either. If you have sand setup in a running SW
tank for a couple years even waste gets trapped inthe lower sand. So if you mix it up by removing it, you can release toxins that you wouldn't want in your new tank. There are methods of cleaning the sand in between transfer, but for that little of sand, I don't know if it is worth the trouble. Not trying to be a pain, just telling you how it is. I just worry that you don't have the cash for the sand for a 10G SW
tank, and that is just a minor spendage in the long run.