Bleach is a very strong oxidizer, like peroxide and K+ permangnate.
It destroys plasma membranes which are highly reduced biochemically(think saturated long chain fats) and produces a by product which is even more nasty and toxic.

Adding a highly reduce compound with a strong oxider will cause havoc at the microscale.

When you add CO2 to a powerhead or a pump, it'll sound much quietier if you use a fine mist air stone to bubble the gas into the suction side, the larger bubbles make an awful racket IME. the tiny ones hardly make any noise and it improves the efficiacy of the CO2 mixing also.


Regards,
Tom Barr