I did this on my 120. By putting in the Y it gave me a back up if the main drain got blocked the flow could still continue and it would make a lg gurgle noise to alert me I had a blockage. My drain was dead silent
I put a valve on my return and slowed the return into the tank, and that has made mine alot quiter even silent. This lowers your flow, and takes life off your pump though, but it was an easy fix and works great for me.