Areas to Check

• If the leak is not readily apparent, it can be very difficult to locate. Check the pool's filter system while it is running. Many leaks can occur in the pool's filtration system around the hose attachments and fixtures. Even small leaks here can add up to a great deal of water loss over time. If you are able to localize the area that is leaking but are unable to find the actual source of the leak, it is time to get into the pool with a few tools.
  
  

Dyes and Food Coloring

• Once you have established the general location of the leak, take a dark colored dye and apply it to the water in the pool around this area with a dropper or syringe. Turn off any pumps and/or fountains that disturb the water. You will need to have a pair of underwater goggles to observe the dye. If you are careful not to disturb the water, you should be able to observe the dye moving towards and out the leak. If the leak is not along the bottom of the liner check all of the seams in the general area of the leak.
  
  

Locating Other Damage

• Once you have pinpointed the leak, check the area for any damage the leak might have caused. If the leak washed out a great deal of the supporting sand, you may need to drain the pool and replace the sand to prevent any other damage to the pool's liner or structure. Once you have repaired any damage, you can begin the process of patching the leak. Unless you drained the pool to make repairs to the foundation, you most likely will need to use an underwater patch kit to fix the leak. Once you have repaired the leak monitor the area to ensure the patch was effective and to look for additional leaks.