Saw about 7 of these last night on my back overflows. I think they are chitons, but if they are they are babies. Very tiny, dry rock was used, but when I first got some corals, I didn't have a dip, qt'd till I did, and saw one. I put it in my dp, and haven't seen it again. When morning lights came on, they slowly moved off. Well, at least I hope they are chitons. Looks like I might have quite a few of them.