Thanks for the great info. I am aware that the Koi forage constantly and dig into the clay. I changed the schedule of the automatic feeder to 5 short times per day instead of two to hopefully keep them occupied.

The Koi seem to prefer to dig holes around the shore that does not have rock in 6"-18" of water. What are your opinions on adding rock to that shore line? You think they will just forage in deeper water?

My aerators are sitting on the bottom so I am going to raise them up.

I purchased the property in January of this year and noticed then the water was very brown. It was a darker brown but still about the same visibility.

There are 13- 24"-28" Koi, 7- 10"-13" Koi and 3 -28"-32" grass carp.

The grass carp keep the pond 100% free of any aquatic plants. I feel that may also add to the problem. There is nothing holding the bottom substrate in place.

This may be a question for another thread but is there a happy median with grass carp to have a reasonable amount plant life or is it all or nothing? My other pond on the property is 1.25 acres and has 10-12 full grown grass carp. There is not a single weed growing there either.