I moved into my house that had a fish pond that needed alot of work. The water is very dirty so I was wondering what is the best way to clean it up. It has no filter/pumping system so I figured I would start there. I had to buy a new liner due to a puncture. The pond is about 13'x 11'

Does anyone use the U/V filters in there ponds?
How well do those actually work?
Will it clean up the water so I can see to the bottom? (4ft)