I bought one and the motor is loud. It hums. The water outflow hitting the water is silent because I adjust the water level accordingly. The filter is as level as can be. I removed the impeller and the shaft and put Vaseline on both like several videos on youtube advise. This took away the slight rattle sound, but did nothing for the humming. I think it's because it flows 300 gallons per hour. I have an Fluval AC
70 and I bought it a week ago. I run it along side my Marineland Penguin 200. I'm hoping to seed the new AC70 with my slightly older Penguin 200. My water is crystal clear. I know that Fluval is supposed to be Hagen's top tier name. Aquaclear is supposed to be one of the best so it was recently rebranded as Fluval 70. It says Fluval instead of Aquaclear on the lid, and the Box is totally different. I'm not sure if anything has changed in the design. Had I had a chance to do this again, I would have bought the sunsun canister filter. Everyone loves them and I've heard no complaints.