If you have been using your pool for 10 to 20 years, you may have noticed that the color of the shell is gradually darkening. This is normal wear and tear on your pool's liner.
Cracks can also appear on the fuselage. They usually occur due to impacts against the wall caused by objects falling into the water. Cracks can also be caused by ground movement that shakes the pool structure. These cracks, if they get worse, can lead to water leaks. Sometimes these are also due to a problem with the watertightness of some solid parts in the pool or in the piping.