Last year I buried a 145 gallon hard shell pond (80" x 54" x 18" deep -
Tahoe model) and installed a Pondmaster 500 gph pump - box said it's
good for up to 10 1/2 feet lift. The pond is about 18" deep and I
stacked flagstone about 12" high to create a small waterfall. The pump
has a 3/4" output and I used a splitter to create 2 outlets that
cascade down over the flagstone. The waterflow is way too weak for
what I'd like. It's less than a garden hose would produce.

Also, the water is constantly cloudy so I installed a "Garden
Treasures" Low Profile Mechanical/Biological filter (Model MF750) . It
says it's for use in ponds up to 750 gallons with pumps between 300 and
700 gallons per hour. It's not a bypass filter, the pump's input is
connected to this filter so the pump draws through it. It's just 2
sponge type filters and some bio balls and it didn't help, the water's
still cloudy and I'm guessing it's restricting the water flow.

What would be a good filter & pump size to go with to create a better
water flow and keep the water clear? This is a little pond so I don't
want overkill but something that will look nice. There aren't any fish
or plants in the pond.

Thanks.