I built my in ground 18 x 26 vinyl liner pool in 2004. I bought a kit online from PolarPools. Iím planning on replacing the liner in a week or two, and Iím curious if I should upgrade the main drain at that time. The pool bottom is concrete, so a wholesale change out isnít likely practical. What would you recommend? I donít know the part number of the original Hayward main drain, but it has an older style anti-vortex cover. Iím assuming Iíll want to change the gasket at a minimum, and maybe additionally change the cover (safer model?). Any advice would be appreciated.