6040 Noise

[Detritivore]

Hello,

I just got a new 6040 nanostream from BRS a few days ago. It's currently in a 20 gallon nano with saltwater and dry rock. I know there is a break-in period, but the noise coming from it just doesn't seem right to me. At 100%, there's a slight rattling noise, and it is much, much louder than my old 6100 from years ago (which is still running, btw!). I can hear the humming of the 6040 from upstairs. Is my unit defective, or is this what I should expect?

Thanks

 

[smatter]

They aren't silent, especially at higher speeds. Mine are quieter without the flow deflectors. They squeeze the plastic just enough so the prop grazes it causing the rattle. The rattle goes away after everything seats itself.

 

[rvitko]

What smatter said is generally true, the deflector causes some water movement inside that results in a little more noise, however, if the pump is very noisy 2 weeks in, we have to assume the propeller is faulty, it fits too loose, it should definitely be quieter than a 6100. If the noise is not improved 2 weeks from now, we will send a new propeller assembly.

 

[Detritivore]

Thanks for the help; here's an update. The noise has improved slightly, but the pump is still quite audible. The rattling hasn't gone away. Here's a video of what it currently sounds like (all other pumps are off): https://www.youtube.com/watch?v=MDxyRRFZG6I

Is this normal?

 

[rvitko]

One thing I notice in the video that could be a cause and would be very easy to test is that the glass/acrylic looks very thin, the magnet on this pump is strong enough for 1/2", if the glass is less than 1/4" it would both transfer more vibration and cause more vibration as the magnet is also pulling on the impeller magnet. If it is as thin as it looks in the video, my first step would be a shim between the outside magnet and glass. If that doesn't solve it, I'll send a new drive unit.

 

[Detritivore]

Hi Roger,

Thanks for the response. The glass on that side is actually already shimmed (the entire side is covered by a thin piece of painted acrylic that serves as the background). So the thickness of that wall ends up being around 5/16-3/8" thick. I put some bubble wrap under the external magnet to see if that would help, but it didn't.

 

[rvitko]

OK, forward me a copy of the receipt, I will send a new drive unit out on Monday-

Tunze at sbcglobal dot net.