steve , thats a lot of fish in a medium sized pond !!!
since your using the pressure filter type , think about adding a bakki , as they can handle heavy loads and you might want to think about upping the flow rate and turnover
the general rule is smaller the pond faster the turnover , and then add higher the stocking rates ,faster the turnover .
just bare the above in mind , as we've all been there , when we first start we want loads of koi ect , and usualy hit problems with over stocking , koi keeping is like a ladder . youl find as you progress , you'l keep less koi in more water !!
steve
