Well I was going to switch over my 35g to the 32g cube, but then at the last moment I decided to buy new sand instead of the old. I was using a really light sand that would get all stirred up and took forever to settle when ever the pistol shrimp would start digging around so I am thinking something a bit heavier but I want something I can keep Pistol shrimp/Gobies/conches on. What would you guys recommend??