I have experience with Koi in a pond. The pond did have a bad FA issue. After the koi went in the FA issue was solved. I never saw them eating the FA but I did see them rooting around and the bottom and tearing and breaking up any FA that tried to grow. The water clarity did be come more cloudy as they obviously stirred up some clay from the bottom. Tilapia now seem to be controlling the FA and I have been Removing koi and see some improvement in the water clarity.
I also have noticed some erosion around the edges where the koi have been digging for worms or what ever in the grass roots along the edge of the pond.
Last edited by BobbyRice; 06/27/16 07:59 AM.
