What is the purpose of the 90 elbow on sponge filters?

[krap101]

I was wondering, because it makes a lot of noise, and I was wondering if I could just take it off?

That clear ribbed 90 degree elbow at the top.

 

[BillD]

It is to move water away from the filter. You might be able to make it less noisy buy cutting the end on a 65 degree angle with the open side up.