I've known and read that running a 2 to 3 inch sand bed is the most practical way to do it. But I have seen and read that running a sand bed that is deeper can be beneficial but if disturbed can cause major issues. I've wanted to try it myself and see what the out come would be. I also knew a guy that never did a water change and his tank looked amazing. There was growth everywhere. What needs to be done to minimize water changes.