I'm beginning to believe it is so.
Apparently, a diet of nothing but duckweed and earthworms is enough to grow tilapia at enormous speeds to full size. I have been thinking about Kurt Saxon's "maggot farms" to replace or complement the earthworms. It seems earthworms can be pretty susceptible to colony dieoffs and other ailments but flies only need a hot bulb and some you-know-what. There's always plenty of that to go around in an underground setting. Sounds like this would be an incredibly low energy system, the sort you could power off a solar panel or two and keep it out of sight.
A garbage bag broke on me the other day and a tumble of maggots poured out. I was looking at them and thinking, man, that would be good fish food.
I reckon if I could put the fish in a bathtub inside my hydroponics rack and make everything work together inside Vault-OS I'd have a winner.