Small punctures are patchable. Old, brittle liners are not.

If it’s a small tear or hole — like from a vacuum head or a toy — and the liner still looks good otherwise, grab a patch kit. Those are quick fixes.

But if the liner is over 10 years old, has turned brittle, or you’re seeing multiple leaks in different spots, patching is just delaying the inevitable. Same goes for large tears, severe fading, or when the liner has shrunk and pulled away from the coping. At that point, each patch is temporary, and you’ll spend more time playing whack-a-mole than swimming.

Trust the feel. If the liner feels stiff or crinkly when you push on it, it’s done.

Replace it when patching stops being a one-season solution.