How do you sterilize ground water before digging a new pond as suggested ? Is it a total waste of time to try to avoid green sunfish ? I'm having a pond dug out that will be fed by watershed and water table when high enough. Neighbor has a small pond 1/2 mile away that has green sunfish in it.
IF the area that you are digging your pond in has standing water in it, I'd consider using hydrated lime to bring the pH up to 11, that will kill any fish.
Like FishingRod says, you don't have to sterilize ground water, just keep an eye on surface water. Fish can move from pond to pond in less than 1" flowing water (or standing water for that matter).
