Get creative pumpto the bottom do a upflow system. Cut the top make a 3" slice down from the top say 8" apart and then bend the plastic over between the cuts and you just made a sheet weir. no ugly pipe ifyourstream is only 8" wide then i'd make the cuts say 4 to 5 " apart... if you use a hair dryer on the roll of the top lip you can straighten that out and direct your water.