I have an old turbo sitting around and thought about this. A quick test of hitting it with a garden hose at 50 PSI resulted in absolutely no movement. giving it a spin by hand and keeping the hose on it it still stopped. So I've switched to building my own out of PVC It's cheap and seems pretty easy so far although cutting "scoops" (not sure what to call the paddle parts when they aren't flat) is taking some time with a hacksaw.