On Mon, 25 Dec 2017 04:20:13 -0800, George Miles wrote:

Is there any reason not to have an earth rod indoors?
TT system.

I've got 2 earth rods outdoors,
can I keep them and add a third indoors so there's less resistance?

What is your earth rod resistance now?
Adding an extra rod is not guaranteed to lower the total resistance.
If you are currently getting 10 ohms than adding another rod will not
really help, however if you have 150ohms or so, then an extra, or deeper
rod may well help.