so for those of you that have used it....how fine is it? is it like beach sand or more powdery. i saw some at the fish store and it was hard to tell through the bag. What are people opinions on the stuff? Had a bit of a tank problem and i am getting a new tank today and all of my fish are in rubbermaids right now. I was gonna try to get 3M quartz but i don't have the time to get it. What do people think of the moon sand?