U can pick up aquarium netting on Amazon. Really fine netting that doesn't block light but keeps the critters in. Might have to get creative fastening it to the top though.
Learned my lesson after a wrasse went carpet surfing...
Sadly it is a common experience With wrasses especially it is not if, it is when they will jump. (flashers especially: even for my water change I was passing the hose under the tilted lid to never ever remove it)
My yellow corris wrasse has jumped 3 times.. once again mike c house... and twice at mine.. one Including today..
Jumped while doing maintenance on the tank... I have a cover.. wrasses are crazy!