White spots

[CarlD]

Sounds like bleach/chlorine landed on the liner and bleached it. It can do that.

[PoolDoc]

Either granular trichlor OR calcium hypochlorite will do that to vinyl liners. Bleach may 'bleach out' an area, but is unlikely to create white spots.

Regardless, there's no fix: once the color is gone in an area or a spot . . . it's gone.

It is NOT a defect in the liner, and fortunately, doesn't seem to damage the liner material itself.