Gives the impression of sand but no sand so you can really crank up the flow.Thanks so much for the info, I will be following for sure. Derek from Miracles is building my 60x24x22 tank right now. I am going with an internal overflow for bean animal because I don't want the tank to stick out from the wall to far, hopefully thats the right decision? If I could ask one more question, whats the reason for the cutting board other than protecting the bottom glass of the tank. I love the aquascaping by the way.