Puffer vs. Mudskipers

as a relatively new member, i have been slightly intimidated by the amazing aquariums i've seen on this website. that being said:

i've got a green spotted puffer that really likes to pick on my three mudskippers. it likes to bite their fins.

my solution to this was to treat the entire tank with melafix (treatment is ongoing), and to build a plexiglass divider with holes in it that would in theory isolate the puffer from the rest of the fish. this has been working, except that the mudskippers are entirely capable of climbing over the divider and into the puffers domain.

i haven't seen any new bites on the mudskippers yet, but i'm scared that it is just a matter of time...

what would a more experienced fish keeper do?

the two options that we've come up with involve either removing the puffer and the divider altogether, or doing more construction on the divider so as to isolate the rest of the fish from the puffer.

thoughts?

thanks for the input. what if i just made a divider that stuck out of the water by a few more inches? i know mudskippers can jump over stuff like that, but would they?

the notion of returning the puffer to the local fish store upsets my stomach slightly on the grounds that they have a habit of selling cool looking, hard to care for fish to idiots for profit, and i actually like my puffer.

it's an 85 gallon tank, with about 60 gallons in it. the gap between the top of the water and the top of the tank is about 5-7". right now the divider extends about 1cm above the water.

i had a 30 gallon with a crack, so that the most water it would hold was 12.5 -15 gallons. i tried putting the puffer in there for about a week, but it was very noticeably stressed out (with the black belly and the ill defined spots). that's when a friend and myself devised the divider.

i think i'm going to extend the divider temporarily until a cooler solution can be thought up.

i'll give the world a real update once i can find the digital camera.