Sorry AZ, no offense, but I have an inherited gene that makes it impossible for me to right paragraphs. You can blame my moma, my papa, or the star stuff I'm made of :-) So Jobe, you say the big hotpool ( the Womb ) will stink after a while if the sand is left in it. I don't remember smelling anything when the sand was in that pool after the 92/93 flooding but my smeller ( nose ) doesn't work real well either. So maybe we are between a rock and a hard place on this issue, we either get a stinky pool, or a sandless deep pool with a void that grows white stuff on the rocks down there, and acts as a collection point for all the muck that settles. Since I can't smell, my vote would be to keep the sand :-) Even with sand, the bottom needs to be vacumed on a regular basis, and what tends to happen is that along with the vacuming some sand goes out the tube and the sand gets gradually removed anyway. To keep a certain level of sand we would have to add some from time to time, we have plenty of that now at DCHS Del Mar, who needs Laguna, we got our own beach now :-)