[Shadetree]

Marco,

I added over 600 pounds to my tank for a 6" sandbed, I used Southdown also. I did not add any other coarser sand. I like the look of the fine sand myself. Once there is a bacterial coating on the sand it will stay down pretty good. You will have to use a turkey bastor for the first week or so to keep the rocks clean but it should be fine after that. I let my sand settle for two days before I turned on my skimmer and then it cleared up in a matter of hours. As for the snails, yes you will have to turn some over manually but I do not know how coarse of a material you would have to use for them to turn themselves.

Scott