The citric acid inside will cause a chemical reaction that results in the bath bomb fizzing, creating bubbles and turning the water into different colors (before it dissolves). Related ...

“When placed in warm water, these ingredients then trigger a reaction that produces carbon dioxide bubbles, making it fizz.” And what many bath-bomb devotees may not even know is that ...

then quickly moving a big bottle filled with water over the top. STEVE:As the bath bomb fizzes, the CO2 gas bubbles rise into the bottle pushing the water out. CHILD #2:1900 millilitres.

Cosmetic company Lush's co-founder, Mo Constantine, invented the iconic bath bomb way back in 1989 ... Lush reckons you'll be "mesmerised by the bubbling audio waterdance of tiny bubbles ...