I use it in my ray tank. It's actually really fine gravel, not quite sand grade. I have used sand from the river before but it was too light colored for me. The fine gravel I scooped up with an aquarium net and made the initial rinse right in the river to get most of the fines out. I then rinsed many,many times with tap water as there were still lots of fines mixed in. After it was rinsed real well, I did bleach it. then rinse again to clean the bleach out. Final step was to completely dry the gravel. never had any problems with it in my tank and have used it for several years. Lots of work, but worth it. If you can hump out the sand and don't mind cleaning it, go for it.