Pool - Pacific in-ground vinyl 27,500 gal
Filter - Hayward Perflex EC65 67 gpm rating with 27 square feet effective filtration area.
Pump -Hayward Super Pump 1.5 hp single speed rated at 65 gpm with 30 feet of head resistance.
There is no 'backwash action'. The filter features a bump handle that regenerates the DE by jogging the grid - something like a piston.