If you have an in ground pond, you may be to use your existing pond as a base and convert it to a semi rasied pond. If you don't have a bottom drain, get one and get a brand new filtration circuit on it. Put the existing Ultima and UV on a skimmer circuit. You would not want your bottom drain going straight to an Ultima.
Perhaps you can attach a picture or diagram of your existing pond so we have a better idea of what you are working with.
-Dan