I am not an electrician but I know just enough to be dangerous. I built my house in 2005. I live in the sticks so no inspector. I built the house myself and wired it myself. Site already had a pedastal with meter and disconnect so my 200 amp breaker box inside the house is a subpanel. I ran PVC conduit from the pedastal disconnect to breaker box with 3 service wires and mixed neutral and grounds in the subpanel. Have had no problems in 16 years. I just realized that I left a 4th wire in the raceway for a pull if needed. The 4th wire is stranded #4. My question is should I use the #4 as a ground and remove the bond screw and clip and separate the neutrals from the grounds and bring it up to post 2008 code or should I just leave all as is? How much safer will it be? Also, I have no ground rod currently in the system. I have buried copper for water lines and have those bonded which I suppose doubles as an earth ground. If I do change to a 4 wire subpanel should I put in a ground rod next to the pedastel and ground the disconnect. I know you guys like as much info as possible so the disconnect is physically attached to the meter box with a steel nipple and grounded bushing.