A skimmer for a Koi pond is different. it is not a protein skimmer, nor does it work the same. It is a device that pulls the pump or filter's water intake from the top or surface of the pond, usually through a floating device. There is no water/air mixture, no column and skimmate. Works the same as surface skimmers in pools. Basically to get debris off the water's surface.
That's all I could find after searching for a half hour... If there is a true fresh water skimmer, let me know, I would love to read up on it!
Thanks!:rollface: