He got into the filter portion of our tank. We got up Monday morning to not being able to locate him anywhere in the tank. My husband had an idea to look at the filter area and sure enough he somehow jumped into the smallest water section. We are guessing he was chasing a copepod at the top of water and just overshot into it. I'm so glad we were able to get him out with a LOT of patience and a small net without any injuries. He was quite stressed but would be more surprised if he wasn't. We have, since getting him out, covered all of the areas with some filter floss. Anyway have any of you had this problem and what did you do to prevent?