Update on my DIY GFO reactor: Been running for 5 days now. I started with 3 tablespoons of GFO. 2 days ago I added 3 more. At that point, flow rate was about 90 gallons per hour. With the 3 more added, GFO did not tumble as high in the chamber. But, still had excellent mix/tumble in the bottom 2 inches. Tonight I switched to a more powerful pump and flow rate is now 130 gallons per hour. Mix and tumble a little more vigorous now and happy no small GFO particles making it more than half way up the reactor. My fear was small GFO particles going through the return. No such problem. I'll continue to up the GFO volume every few days. I'm still way under the amount recommended by BRS on the container which if I recall is 1 tablespoon per 4 gallons of tank. Mine is 55G (70 including sump) so according to BRS I should be running 14-19 tablespoons.