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.
	
		
			
		
		
	
				
			 
				
