I love my Skippy Filter but as my fish have grown so is my overall fish load and even though its a 5000 gallon pond, too many fish and too big of fish are starting to overwhelm the skippy. I planned for that eventuality in the beginning so I have a space set up to expand with another Skippy or add a Bog. The Bog is what I have decided to add, like I said I love the Skippy and will keep the original but I think the advantage of having a bog outweigh having 2 Skippys. Upshot of all this is, go with whatever you want initially but make plans in the beginning for upgrades NOW and in the future you have the flexibility to change if you want to. goodluck, Tim