Agreed
the grow in my sig I decided to stop and I ignored for over a month after that with just an auto top off barrel to see what would happen.
They were huge, healthy, and busting out of that 5x5 when i chopped them down. No air, just strong waterfalls, hydroguard, and a little temperature management.
my air pumps are loud, I hang them in the backs of my tents so the sound of the water drowns them out. I can hear the one on my mother box right now from where I am sitting. I just dont mind the ambient noise as I hate silence anyway lol.
Also agreed on bacteria, but everything gets a peroxide bath going into next grow anyway. After everythings cleaned from heavy deposits it gets run with a fairly heavy peroxide solution for a few days then rinsed a couple times. Even boiled all my stones in our biggest pot.