Eheim 1260 makes my house hum !!

[tcyiu]

My new Eheim pump situated underwater in the sump emits a powerful low pitch, low amplitude hum. The floor near the sump vibrates.

I am experiencing peaks and valleys within my living space. Depending on where you stand within a 15ft radius, the hum varies. In other words, in some places, the hum is louder, but becomes quiet if one moves over by a couple of feet.

To mitigate the hum, I have the pump sitting on a couple of short segments of vinyl hose (acting as "rubber feet").

When I first got the pump, the flow was too great, I restricted the output to 1/2 inch plumbing (should be 5/8), and added a ball valve to cut the flow back a tad. In addition, I modified a prefilter from a power head and put this on the intake of the pump.

I wonder if I had "starved" the pump, causing it to go out of whack. I have since taken the pre-filter off and the hum seems to have diminished a tad.

Any other ideas. I am generally happy with the setup, but I spent the extra bucks on Eheim because I wanted complete quiet which I'm not getting.

Tim

[discussmith]

No guarantees but you could try a couple things. First I would put a tee on the output and put your ball valve on one side and allow this output to dump right back into the sump well. Allow the other side of the tee to extend back into your aquarium like before. You can then slow the return by opening the valve and allowing more water from the pumps output to just dump into the sump well. This will not restrict the pumps output and possibly quiet any vibration. If there is still vibration you could possibly dampen it from transferring to the floor by placing foam pads (like mouse pads) under the sump. Your restricting of the output is the way you are supposed to slow a pump without damaging it so you should be ok. It may be however that it was causing this vibration which sounds to me like it is creating harmonics with the surrounding structure.

[tcyiu]

No guarantees but you could try a couple things. First I would put a tee on the output and put your ball valve on one side and allow this output to dump right back into the sump well. Allow the other side of the tee to extend back into your aquarium like before. You can then slow the return by opening the valve and allowing more water from the pumps output to just dump into the sump well. This will not restrict the pumps output and possibly quiet any vibration. If there is still vibration you could possibly dampen it from transferring to the floor by placing foam pads (like mouse pads) under the sump. Your restricting of the output is the way you are supposed to slow a pump without damaging it so you should be ok. It may be however that it was causing this vibration which sounds to me like it is creating harmonics with the surrounding structure.


Been away at some all day meetings so I was not able to get back to this.

I have not yet tried the solution with the T. I think I may do that when I get a chance. But what I did do in the interim was to pad the sump's bottom with a bunch of "Squeeze Donut" toys from the local Dollar Store. Essentially, these are silicone rubber donuts filled with a liquid. They're soft and squishy. Because they are rings, and not balls, the sump won't roll around. The sump is now "floating" on these rings.

My subjective feeling is that the hum has been reduced by a sizeable percentage. But the hum is still there. I think discussmith is right. The sump is a resonant chamber and there are definitely some harmonics at work.

I will try removing all plumbing and see if the hum is diminished with NO water resistance.

Tim