Pressure Test Plumbing Lines
Regardless of the suspected location of the problem, a pressure test of all plumbing lines should be done to confirm whether the leak is in the plumbing or the structure (shell) of the pool. Using the process of elimination, pressure testing allows you to conclusively isolate which part of the pool is leaking so later location procedures can be efficiently targeted. If you find a pipe section that fails the pressure test go on to Step 3. If all plumbing lines hold pressure, skip to step 4.