I'm curious what other's opinion are on this matter. I know BRS' opinion on this, but I personally have had bad experiences with not tumbling carbon in a reactor. What happens every time I tried using carbon and not tumbling, the flow through the reactor would weaken to the point of around 10% of the starting flow in 2 weeks typically. Then, when I would open the reactor up to replace the carbon, the previous 2 week or so old carbon would smell like straight sulfur. Does anyone else still tumble carbon and if so, does it work for you?