if you need a pump that is quiet, these two are nearly silent and both push about 1200 gph:

sicce 5.0

blueline velocity t4

i have had both on my tank - started with the blueline but changed to the sicce because of the amount of heat that the velocity put into the water. the pumps are so quiet that the only sound coming from my tank is the pulsing hum from the tunze wavebox.