Gfo needs to tumble so the particles won’t bind together. If you mix rox with gfo, you can get away with a slower rate of flow as the rox helps keep the gfo from binding together. Rox is also supposed to be hard so it shouldn’t turn to dust when mixing with gfo.How does that work mixing carbon and GFO? Doesn't GFO needs to tumble to work? Carbon is not suppose to tumble. Is it because of the smaller size of the RX it can tumble?