marineland 1100 pump noise

[andycook]

I'm using two marineland 1100 pumps as returns from my sump to my display tank. There is about 6 linear feet of .5" flex pvc, two 90's and one 45* on each run. They are stuck to the bottom of my sump on their suction cup feet. My problem is there is a very distinct hum from both. One is a little louder than the other. I can feel a very distinct vibration when I hold the flex pvc.

My first thought is that the pump is undersized and working too hard thereby creating the vibration. Does that make sense? Any other thoughts?

 

[andycook]

Based on the suggestion made by ...no one I took the intake covers off but that made no difference. Keep the suggestions coming.

Next I am going to try to isolate the flex pvc from the sump frame. I'll also put a mat or something under the sump to dampen the sump vibrations.

 

[andycook]

I shortened the flex pvc and arranged the pumps so that the flex pvc isn't leaning against the sump side. I then put a rug under the sump. The noise is reduced but it is still there. Not a problem when I am blaring Pink Floyd concert bootlegs from the 1970's but not enough.