Got a call for a pool shocking. Checked all bonding using continuity first then did a neutral to earth voltage test. Pool water .5 volts. Concrete 3 volts, hand rail 3 volts, heater , pump and at ground rod 3 volts. (Fiberglass pool). So different potential with pool water and concrete. Pool plumbing also has 2 water bonding fittings plumbed in line and bonded to grid. This is all on the west side of the pool. East side of the pool has only .5 volts on concrete and in earth. This is all present with main breaker to the house off. When I disconnect the bond wire and ground rod all voltage at pool is equal at .5 volts. But I still have the 3 volts on the neutral at the main panel. Re connect grounds and 3 volts back again at pool concrete. Installed 2 new ground rods at service and no changes. Any thoughts?