I just lost my favorite clown, a midnight with an orange nose. He managed to find a hole in the netting that I had covered the back sump where another clown had perished a few months ago. My bad for not making a better cover, but this really is a poor tank design.
Here is my post after losing my 1st clown. I will have to come up with a fool (clown) proof system.
>>I have a screen top over the 45g, so no jumpers there. My 23g JBJ Nano has a top but I've had clowns jump over the partition, one managed to get himself sucked into the impeller, I rescued the other. I've since put netting over the compartments with enough water over the netting that a fish should survive until I can return it to the tank.<<