I thought I would add my experience with play sand, I HATED IT!!! I washed and washed it and had it in the tank for a month and the water stayed cloudy. All three filters were caked with mud and it covered my rays constantly. I finally got fed up, pulled it all out and put my fine gravel back in. I know its a big debate, gravel, barebottom or sand for rays but my 3 (1 motoro,2 retics) are as happy as ever. Its almost as if they feel better because there not ingesting all of that damn mud from the play sand. Stay away from play sand, suck it up and pay a little more for the good stuff, just my opinion.