Yesterday I bought a yellow watchman goby, he's a really little guy, and he's spent most, nearly all, of his time at the top of the tank. He's already gotten sucked into the overflow once and made the journey down into the filter sock as I tried to retrieve him. Not sure why he's hanging out up there. Possible afraid of engineer goby? Ammonia nitrite and nitrates are all 0. All other fish are acting normal and haven't really paid much attention to him. The engineer hasn't really bothered him at all. So I guess my question is: should I move the watchman down to the refugium until he gets a little bigger? Or just wait a couple days to see if he moves to the bottom of the main tank?