you know what my chemistry class did once... filled a GARBAGE BAG with industrial bottled hydrogen and oxygen (after electrolysing small quantities ourselves), tied it to a 3 metre chinese visco fuse, lit it and let go, this was after a fireworks show and the sky was clear of planes.
ssssssssssssssssssssssssssssssss*way up in air*ssss BOOOOOOOM like a firework but much bigger, louder and more fun!!! muahaha the flame from the explosion was like lightning, it lit everything up for a split second
I hate hydrogen gas, my electrolysis cell pumps out a shit load of it and chlorine gas. So I have a highly toxic potentially explosive garage sometimes.
Hydrogen balloons are nothing compared to large flash salutes