Im going to try corals for my first time in a 20 gallon flat back.just wondering how much(deep)of sand to get.I also didn,t want to pay alot for live sand at local pet shop and wanted suggestions on were to get sand be it dry sand at fish store and have it seeded by some one or get sand from pool supply.trying to budget have slowly got everything else needed except sand,rock,and of coarse coarls.some one suggesteg lineing bottom of tank with eggcrate to protect it just wondering your thoughts on that.finally how much live rock should I get my only filter for now is a emp.400.sorry for all the questions I know there basic I just want to do this right.thank you for any advice you give me hope to be joining with a active reef tank soon if this one goes well Im sure I talk girlfriend into biggerr one!!!! David B