Installed an electric fence with (3) x 6' ground rods and not getting a good enough ground.
How do you know?
Unless
you stand on the ground with bare feet (or wet footwear) and touch the energized wire, you cannot tell what a farm animal would experience.
The soil is sandy and dry.
Which
could form an insulator, for your feet and the feet of any farm animal.
If I touch the chain link fence the insulators are attached to and grab the wire I get a big jolt.
This shows that the chain link fence
is effectively connected to the return path (Ground.)
Did you
directly connect the fence to the Ground terminal or to the Ground Rods?
If not, it indicates that the metal chain link fence
is effectively connected to the return path, via those Ground Rods.
Since you have a metal fence (presumably, with metal pole supports), you might as well use it as a part of your Ground/return path, since those metal poles will act as numerous Ground Rods.
One winders why you
need an electric fence on a metal chain link fence.