Yes, you need a ground probe which is there to save your life. Forget the induced voltage which will always be less than 108 volts. If it is 108 volts or higher, that is a short and if you put your hand in the water it will throw you across the room which has happened to me many times before GFCIs were invented. Put in a ground probe for your own good. I do not like to go on these threads because of all the opinions and arguments from some people who don't understand electricity.
