I use two panworlds, the first is a 50PXX - 1100 gph that runs 24/7 @90 watts. the second is a 40PX - 480 gph@ 45 watts and runs 8am to 10 pm. Both pumps are quiet running together, the noise from the water drowns out the pumps, when the 40px drops out the tank becomes very quiet at night. To compare if I ran 1 panworld 100PXX I would use 130 watts at only 1270 GPH and not have the ability to slow down the flow at night. To add I also have a Tunze Wavemaker