LOL I do often find it difficult to get out the classroom when the bell goes for breaktime on account of curious little year 7's wanting to see the "big weird fish". Although during lesson times the aquarium seems quite useful, I think he has a calming effect and I sometimes notice students staring into the tank and pondering before becoming engaged on task.
Rho only comes home for the 6 week summer break and spends the rest of the year in school. For 2 week breaks I generally feed him very well about 10 days prior to going away, giving him a big worm every day. (as opposed to every 3 days or so) Before I leave I give him a couple of bags worth of live bloodworm (they seem to keep him going for a few days if I spread them around the tank so he has to hunt around a bit) and also chuck in as many cherry shrimp as I can spare from the other tank.