well the tank has a canopy on it. the only place to jump is out the back. and they have to options from there. off the wall into the sump or just straight into the sump..... but what are the odds that 2 fish would jump out of a tank on the same night? The clown I already had in there is still there. nothing wrong with her. There were apsolutley no signs that either of these fish were in bad shape.