Does anyone keep a functional culture of live food in their main tank? For years after unintentionally introducing them, I've had these small red worms, they look like an annelid of some sort. Occasionally I see my fish pulling one out of the substrate. While watching this the other day, I was wondering if anyone else has some fish snacks living in their main tanks. I'm sure many have "feeder" tanks running, and cultures in the fridge, but do any of you have worms or copepods, or anything else with a sustainable population living in your tank?