Thanks, Fritz. I tried that trick, bigger fans, lower speed, but with my cheap fans, the motor noise increased when I lowered the voltage!
Anyhow, I've decided to get 4" ice cap fans.
Does anyone have advice on whether I need 2 or 3?
My tank is 55g (14" x 48" x 24"), with 2 X MiH 250W.
Thanks!
Ty