lol - the water trickles slowly on the sides of the bowl. You REALLY can't hear any water activity at all.
My computer now has one 80mm fan for the Enermax PSU and an unsilenced WD 120GB JB HDD. That HDD is louder than the fan, the pond pump and anything else.
That's showing you how quiet this setup is.
Now the ambient temp is just under 19C (was 24C before during day) and the temps are 46-47C idle and 51C max.