This may sound like a dumb question, but how important is having an air source like an air stone or strip for bubbles? Do the bubbles actully help with aeration that much? Is it necessary for the fish to have it? Thanks.
the exception is if the tank temps are high. either on purpose or due to natural reasons.
don't get me wrong..the gas exchange occurs mostly at the surface where a lot of water is exposed to air.
but if the tank temps are unusually warm (84+) you should ad airstones to create more turbulance to increase the amount of dissolved O2 in the water.
warm water holds less O2.