Kimi, the kind that you posted, or at least true micro stars, are often found on the rock, or if you keep a crushed coral bottom, they keep it clean. If you really want some, order some GARF grunge. I am about to order some in the next week or two to kick start my sump. I do not like getting all my LF from the LFS, because they usually order from one distributor. This allows for only so much biodiversity. If you have any local reefers, or you get a chance to trip on down to ATL, ask a few members if you can trade a scoop of sand from well established tanks. If you buy some good rock from the tank at your LFS you saw them in, chances are you will get a few, and they will multiply. The stars that look like "half of a star" or small stubby ones, those are not so good. The long tentacle ones are good though.