DSB work best at the display tank..where most of the solid waste will be accumilated... swallow sandbed in the sump is enu to turn it into food producing refug
Not the latest pic..but thats the GSP im talking about..the one sticking onto the back of my tank..ive glued them onto smaller rocks..will snap the pic soon.
http://linux.cks-net.org:8080/pic/aquarium/aug03/left.jpg