Maybe perform your jar test again?

You might try leaving one jar in a room that receives indirect sunlight and one jar in a very dark location. Another check on what is causing the current turbidity couldn't hurt!

I failed to list a third option. If your water looks like coffee and cream (NOT just following a rain event), then mechanical stirring of your pond is a likely cause. That should definitely show up on your jar test. Both jars should clear in a few days and exhibit some silt at the bottom of the jar.

If that is the case, then I suspect that you still have some fish physically stirring up the bottom of the pond. If your giant carp was not a triploid (sterile) carp, or not put in as a single individual, then you almost certainly have more carp. Hungry channel catfish will also stir up the bottom searching for food. Any chance that bullheads have been introduced to your pond? They can be very prolific, resulting in lots of little bullheads stirring up the bottom.