So this is just a rain barrel placed on a reinforced carport roof top. It’s about 10 foot off the ground. Pond water gets pumped into the bottom of this barrel, fills it up and overflows/returns out the top of the barrel’s standard 2″ port. The pump’s flow rate is faster then the overflow rate so a ping pong ball float valve is used seal the air vent and force water through the return line. With out an air vent (closed system), the barrel would collapse in on itself from suction as the water travels down the return line. Once again, I’ve used rattail cord & friction hitches to keep things in place and I can just slide up the knots if I need to access the check valve.
Here’s it in action: