Do I Need Air Bubbles?

My aerator is very noisy. Do I need it on ALL the time or can I turn it off at night?

Provided there is a filter in the tank, bubbles are mainly for aesthetics. The only time an airstone can be useful is when you have to medicate the tank. A lot of meds reduce the oxygen content of the water and the bubbles help to get more oxygen dissolving by churning the water up so the surface, where gas exchange occurs, gets moved round faster.

But the filter needs to run 24/7. If your aerator is a venturi and part of the filter, you can't turn the filter off but you can disable the venturi function overnight.