1-2"would be beneficial to you. I had about 2" in the back, tapering down to 1" in the front of my old 20. (I posted some pics on another thread that you started on here) I had a Yellow Watchmen Goby, Fancy Serpent Star, and many types of snails and crabs. There were all sorts of little "tube like" worms that would build a small 1/2" tall tube from the sand, and there would be 2 clear very thin, long arms sticking out of the tube and blowing in the breeze. I had no idea what they were, but definately some type of filter feeder, which helps keep things clean in a tank. Personally, I can't stand the look of bare bottom, but thats entirely up to the tank owner. Yes it's easier to suck out detritus with a bare bottom, but if your system is set up properly in regards to flow, skimming, and CUC, there is really no need to ever suck out detritus. Also, with a sandbed, it gives you an extra buffer zone, where if the power goes out, or you become lax on tank maintenance, a sandbed will allow these things to have somewhat less of an impact on your water quality. Hope that helps some!