Cascade 500 Too Noisy

[downwiththesickness1975]

I have a cascade 500 internal filter and when it is attached to the side of the tank via the suction pads it makes a real racket.

If I leave it freestanding it doesnt seem anywhere near as noisy but because of the flow of water wont stand free properly.

Does anybody have any ideas that may help solve the situation.

Cheers