I have gained a lot reading here. Thank you. I have a big slide that has a 15 hp pump with a 6 inch line I want to figure out a cost effective way to supply the pump safely. My ideas so far are to put in 4 main drains and gravity over to a sump well 9 feet deep then the pump for the slide pulls out of that or a large wall grate that extends above the top of the water line and make a stainless box that the pump for the slide pulls out of. I have not built this pool yet but want to get it ordered. It's a 20x40 rectangle. (Yes, I understand the danger of suction from a pump.)