• A leaking swimming pool liner is a serious problem that must be corrected as soon as it is noticed, because it compromises the integrity of the pool and can lead to expensive water bills and repairs. While it may not be possible to actually see the leak, there are some signs that point toward a pool liner leak. Once any of the signs of leaks are noted, have a professional pool repair company evaluate the leak and fix it.
  
  

Abnormal Water Loss

• Water evaporating from a pool is normal, as is losing water to splashing when people are using the pool. If the water loss in your pool seems abnormal, you may have a water leak. Keep track of how often you have to refill the pool. If you notice a big difference in the number of days between fillings, you may have a pool liner leak. The amount of abnormal water loss will vary depending on the location of the leak. A higher leak means that you won't lose as much water as you would if the leak is lower.
  
  

High Water Bills

• It isn't easy to notice water loss problems if you have an automatic fill device on your pool. In that case, a dramatic increase in water usage is one sign of a pool liner leak to look for. Of course, it is natural for the water bill to be slightly higher than normal when you first fill a pool for the season or when you drain it to clean it and then refill it again.
  
  

Visible Damage to Liner

• A visual inspection of the pool liner may show you that you have a leak. Look for tears in soft liners or cracks in hard liners. Any signs of damage to the liner should be checked out by a professional as soon as possible, as cracks or tears can spread until the liner is damaged beyond repair.
  
  

Damage in the Yard

• If the crack in your pool liner is causing water to leak underground, you may notice wet spots in the yard or areas where grass isn't growing properly. According to Anderson Manufacturing, you may also notice that a pool deck or other structure seems to be settling or cracking.