At this point I'm pretty sure a pathogen has infected both my peppers. There hasn't been new growth on either in a few weeks, the old growth looks wilted, and both varieties have little gnarled buds. The three fruits on the mirasol have all split open & then turned black and shriveled. The old leaves continue to grow larger, though.
I can't identify the culprit. It reminds me, of all things, of the bunchy top virus, a disease here that affects bananas.
I'll try chile peppers again, but at this point I think I'll wash the unit & use it for herbs. I have a couple pods on reserve that I'd like to try.