Covering Tank Top

[Blue Ram]

Well I now have to cover my tank - 120 gal - 48 x 24 x 24 (no centre brace) as I now have fish that are prone to jumping! Learned this the hard way yesterday after losing a new fish. Thought I would be OK for 18 hours! Guess not.
My options are glass, eggcrate or some kind of netting. Will eggcrate diffuse the light at all and would dartfish be able to get through the openings?
Glass will be a pain to keep clean and I will have to get it cut so that I can lift up a section to feed. Will gas exchange be limited having it completely covered in glass?
Would netting not sag in the middle and end up in the water?

Looking for some suggestions on what would be best and detract the least from the beauty of the tank which is why I did not want to cover it.