In the process of revamping my 55g mixed tank (LPS & softies). Adding a spray bar and have questions about sand. I have always used live sand, but never really had some solid advice on how much should be used. Also have been hearing about deep sand beds but don't know much about them. BB will not work as I simply don't have the flow required to keep it operating smoothly. Could someone please describe DSB and it's pro's & con's compared to SSB? Also, how much sand is appropriate for DSB and/or SSB?