HELP! What have I done?

[Curious1]

I’ve made huge mistake and don’t know what to do. I finally bought my new aquarium and set it up last night. I didn’t sleep a wink last night because the water pouring back into the aquarium from the filter sounded like a trickling faucet or pouring water into a glass all night! The pump on this filter is not the problem it is very quiet. The problem is the water pouring back into the aquarium from the filter. This is a filter hanging on the back of the outside of the tank. Does ANYONE have any ideas on what I can do to silence this? If not I’m going to have to disassemble everything and take it back. *sad*H2 Thank you.