Finally decided to convert my ATS to UAS and it's a minor tweak to my ATS system. All I have to do is flood by ATS box, set the screen above the anchor bubbler and convert the drain pipe from the tank to fill the box. Now the system is significantly quieter than the water fall type. All I hear is my Fluval Q2 (which I barely hear it) and a little bit of the return pump. Hoping to see big improvement in few weeks. This whole system seats on top of my sump