How to contain jumping fish

Buy a piece or two of acrylic at Menards and fit it horizontal with the back of the tank and the canopy. You can work with it easily to cut out areas for your overflow and wires if needed.

 

Fiberglass window screen or egg crate.  Make sure the window screen is not the mold resistance treated kind.

 

What kind of setup do you have? Lighting? corals? I would probably just cut out a piece of egg crate.

 

Well for my jawfish tank, I used white eggcrate and covered it with fiberglass screen and used that to cover my tank top. I also have a canopy with an exposed back but I didn't want to tank any chances. There is some reduction in lighting but I don't know how to measure it.
I considered eggcrate only, but the fish are small enough to jump through the eggcrate holes. I tied the fiberglass screen to the eggcrate using fishing line. I also cut a small square opening in the front of the eggcrate but left the screen flap so I had a way to feed the fish without removing the canopy and eggcrate.