if you point the bar downwards, or even down and to the side so the water hits the glass at an angle going down, it might be less noisy.
if you use the spray bar, be sure to put those suction cups to use. otherwise when your turt decides to climb all over it, bit it and get behind it, it might get wrenched out, and possibly turned upwards spraying the air, and any lighting you may have suspended over water.
and that's bad.. :]