Hi I am new to ponds and also forum posting so please go easy on me . I had a idea to build a pond and just started digging and researching as I went . While I'm sure many mistakes have been made I am hoping for some advice on my main issue . My water is murky and I can't see the fish . Some back round ... My bottom pond is about 1700 gallons with a pool liner ( I know it will be needing replacement ) it is virgin vinyl Chemical free and thick . I have a underliner under it as well . I have a superior 1:3 hp pump with 1/4 inch tubing going up about maybe 10 ft of head . Which acording to specs is pumping plenty of water . It leads up to a upper preformed pond I have fabricated into a waterfall . The hose goes directly into your pond threw adapter. I also have a 600 gph fountain pump I run in back of lower pond just to stir water up so no mosquitos come . My big thing is I know I don't have any filtration and funds are limited . I am wondering if I can use material and lava rocks to make my upper pond a filter system as well????