I am following this trying to see if i can use some of this in something I am building, a rotating algae scrubber powered by water outflow from an aquarium tank to the sump, it looks like i will have to add some flow from a separate pump to get this to work. My paddle wheel blades will have to be a small percentage of the total area of the paddle wheel due to needing area for algae to grow from what i see so far.. The paddle wheel with be approximately 12" in diameter, and 36 inches across and water flow is about 200 gallons an hour... The paddle wheel will be only slightly submerged to cut down on friction with the sump water, carry on, i am still following...