yeah i have them. first saw them last night. scared the *#&^% out of me i thought they were isopods. so i asked on canreef if any one knew what looked like small sand fleas and was told that they were amphopods. that they were a good thing as they come out and clean up the excess at night. hope this help you out if not try posting your pics and question on canreef for a better awnser
have a good one
Justin