Heres mine, 200 US gallons. Filter is the hydroponics pod. If it works it'll grow. The two elbow joints are stuffed with pot scrubbies (~10 gallons) which I wish I hadnt done cause if they clog the pond will end up on the bedroom floor! I was going to fill the tube with gravel, but made some gravel filter beds and they all clogged very quickly, then read an aussie site where the guy had filled 100's of meters and had to empty the whole lot 3 months later. If I can find some 25mm gravel I'll put that in.