Tunze 6205 noise/vibration

[Neroon]

I recently purchased a 6205 and added it to my 180. I also have a pair of seven year old 6000s in the same aquarium which I absolutely love and I based the new acquisition heavily on that experience. The 6205 works fine, but it has a noticeable buzz or hum to it. The pitch and volume increases as the 6205 increases power. Even at its lowest speed though, it is MUCH louder than my two 6000s combined. They are all but silent with an ear right next to them whereas the 6205 is very annoying across the room. I ordered the 6065.650 mounting clamp per a suggestion in another post, only to find that I already have the same mount. I also tried inserting additional material between the outside magnet and glass in case the rubber dampers were becoming too compressed. Again, no change. I also confirmed that the screen is securely attached. Lastly, I read in this post ( http://www.reefcentral.com/forums/showthread.php?t=1992899&highlight=noise) that the noise should subside with break in. I'm approaching one month though and I'm not hearing a difference.

I guess my question is simple. Is this normal? Should the 6205 running on its lowest setting be substantially louder than a pair of 6000s combined? Do you have any further suggestions?

Thank your for your attention.

 

[rvitko]

Noise questions are very tough to solve without having the pump to test. A 6205 will be much louder than a 6000, it produces 3 times the flow, it is a stronger pump, it should be about 2-3 times louder than the 6000, which spins at a very low speed so this greatly reduces the noise. A 6000 is doing about the same RPM at 100% as the 6205 at 50%. The 6205 also has a larger propeller which results in more reverberation. If it is much louder than that I would suspect there is something off with the drive unit, it may have a bent shaft, you can check this by rolling the shaft on a flat table. It may also have some burr or material stuck between the magnet and shaft or the disk may be damaged or defective. The disk will have a groove that should face up, this groove serves to pass trapped debris and allow water to pass through between the shaft and drive magnet.