So with my new build I have 2 mp40 pumps to use on it. Got them set up and they are loud! Now I know form my mp10s I need to adjust to find a sweet spot. Yes, I found the same applies to the 40s but when I rev up past 50% the vibrational hum is unacceptable. I see the wet side disassembles for ease of cleaning and I have fiddled to make sure it's all secure. While one pump is used and the other new from rebate sale offered in Dec. they both do exactly the same thing in regards to noise. I measured the glass and it's 5/8 thickness and adjusted the spacer for this. Any ideas? Is there some break in period? I'm thinking of going to use my mp10s as they hold fine and while not as much flow per unit! I have 3 on my 55 and like I said more silent even at max.