Originally Posted by ScubaSteve (Post 644027)

I've done it both ways now. Just couple of weeks ago I used old sand that I washed the bejeezus out of. Super hot water in a buck 1/3 full of sand. Mix and wash it until the water coming out of the bucket is clear. Rinse and repeat.

That being said... After my swap I had a way bigger cycle than expected and it took down most of my nice big show piece colonies. @*%$. The rock stayed wet and warm during the swap, so the only thing that comes to mind is possibly the sand.

In hind sight, I think I'll just buy new sand from now on.