I will be getting a new spa with 4 wire connection. I have existing 6/3 wiring to the location. 6/3 goes from service panel 50am to far end of house 50amp gfci breaker box for spa then through conduit to spa. Question 1 is I'm assuming I can use the bare ground as ground plus it's smaller than the other wires or doesit need to be insulated? That said, someone had said 6/3 is fine indoors. Can I then use the 6/3 w bare ground to the spa 50a gfci breaker box mounted other end of house then run 4 wires with one being green insulated to spa essentially connecting the smaller bare ground and green insulated ground together at the gfci box? Trying to avoid pulling a new wire or wires from service panel to GFCI spa panel which is about 100'.