When should I replace my pool liner instead of patching it?

Replace the liner when you see fading, wrinkles around the shallow end, and unexplained water loss together. Fading means the vinyl is brittle and likely to tear. Wrinkles mean the liner has stretched out of shape. Unexplained water loss usually indicates a pinhole or tear beyond patching. One sign might be manageable, but two or three together mean a new liner is cheaper than repairing structural damage from a blowout.