I'm setting up a new tank (RS Reefer 425xl) and I was really excited about the Vectra M1 pump because of the control and because people claimed it was silent. While I like the control, I've found it to be far from silent. I've checked all the obvious things (its fully submerged, not vibrating against the sump, connected to plumbing with soft, silicone tubing, etc). And I've contacted Ecotech support. They asked for a video demonstrating the noise, and pictures of the inside of the pump (you can see them here). And then they sent me a replacement pump after taking my credit card to ensure I return the first one. The second pump, which can be heard here, sounds exactly the same. Now they're asking me to take this one apart and send them pics of the inside of this one. They're being responsive, but I'm starting to doubt that these things are really capable of running silently. I know others have reported noise problems with the M1, and I'm wondering if anyone who had these problems has ever gotten one to run silently. I'm also interested in other recommendations for a truly silent return pump, since it doesn't look like this one is going to work out.