I currently have an old Hayward S200 that needs replaced, 3/4 hp Super Pump, 9000 gallon inground, 1.5" piping. The top mount filters are cheaper so I'm thinking about a Hayward S220T or a Pentair Sand Dollar, but I'm not sure if it will work with my setup. My S200 sidemount has an inlet, discharge to the pool, and discharge to waste. From the pictures I've seen, it looks like the top mounts only have an inlet and a discharge. How does it pump to waste and will it work for me?