Well here is what I tried out today and it was sucessful. I lowered a plank of wood across the pond with the Sterlets and a few Koi in one end and the majority of the Koi in the other, I feed the Sterlets end sinking pellets and the Koi end floating sticks etc, I then lifted it up and tried again so all the Koi got feeds on both side. It took a while so I am looking to modify it to make it quicker but at least it worked.