Best sand I've used since I began salt in the mid 80's. The bag I received last was 7 lbs shy. Otherwise it's top of the line product. I built a wall of liverock on top of a bed of this sand, topped off with RODI IO. A family member dumped nearly a full 30 grams of marine flakes then the current instantly sacked it under the surface, I tried every way of removing all I could. In no time the tank turned cloudy and here I just finished setting it up and this happened, after I did all I could I finally retired for the day.After my six hrs sleep I got up and went into the front room, naturally first thing I looked at the reef tank (I promise this is real and true) and I can't believe my eyes, I got up and went to the tank and the whole thing was crystal clear, all I had was the one foam filter block, the liverock and livesand, all purchased at Amazon.com ! Right away it told me the liverock and lives sand had to consume all of that massive dump of flake food. This happened within the past 4 - 5 months. I cannot believe it myself ! But it truly is true...I just cannot believe it's possible that it biologically consumed all that fish flake food within 5 to 6 hours as I slept. Good liverock and Good livesand! Excellent products Amazon !!!