I used sand from the beach when I lived in Florida; I mostly used sand from the shoreline in the area that was tumbled from waves. I also sifted it to check for anything that might be nasty or broken glass or trash before I put it in my tank. I wound up having some interesting stuff crop up in my tank! but I also was doing a Florida biotope so I wasn't too concerned about anything that may or may not have been in the sand/water. I basically just wanted to see what would happen lol. So I'm not exactly telling you to "go for it", but moreso my experience? At least, I'd probably rinse it and sift it to be sure you don't have any nasty surprises.