As for the substrate you can go with half argonite and 1/2 live sand. How deep would you want the sand bed. We can't really tell you a depth because its all in what kind of apperance in what. Do you want a deep sand bed which is 3" or more or do you want a shallow sand bed? If You can get an idea of how deep you want to go let us know and then we can go with how many pounds of live sand and how many pounds of argonite to use. Also the tank dimensions. Thanks.