Process of Elimination

1. Fill pool to normal operating level.
2. Plug-skimmers, returns, Jacuzzi steps, Polaris, bottom drain (if possible), etc.
3. If leak stops, the leak is in the plumbing. If not, eliminate one item at a time or pressure-test; there is no need for a diver!
4. If leak continues, but stops at the bottom of the skimmers, it may be one of the following: 
• Possible cracked skimmer (with plugs in place): if you find the water has dropped in one skimmer, you have found your leak.
• Skimmer gaskets - you may need new gaskets, or there is a cracked faceplate, a cut/hole in liner surrounding skimmer, or the leak could be through a screw hold. Check all carefully.
5. If leak continues, you want to make sure that the return gaskets are good and the faceplates are not cracked. You may want to see if the water drops below fittings.