Don't even risk it. You'd have to take out half the water at least just to be safe imo. If you do that you're keeping a bichir in a pretty small amount of water etc. Bad idea, get a cover...anything..i use glass shelves on one of my tanks so my fire eel doesn't escape.
don't even think about it keep the bichir in a tank with a secure lid.I had one jump verticaly 1.5 feet and horizontaly 2-3 feetwith no difficulty what so ever
A 12" bichir can jump as high as 2 feet or more. One of my lap jump out of a rubbermaid tub and the water was only 7" deep. The tub was about 2.5 feet tall.