Awesome to hear about the nitrates. Think it was the new reactor that made the difference or did you change anything else?
My pellets stopped tumbling the night before I left for vacation. (Ah Murphy, you and your silly little law, you..). I swapped out powerheads, cleaned out the sponge, nothing I would do would retumble them. So I swapped out pellets as a last resort. Still no tumbling.
Not sure what happened that they stopped like that. I'll try poking around some more when I'm back, hopefully things will limp along in the meantime..