If you go back in my posts, you'll see that I discussed vegans. Not everyone eats meat. If you check the economics of aquaponics, you'll also see that over 2/3rds of the income comes from veggies, not fish.

Don't get me wrong, remember I'm a tilapia breeder. I'm not trying to replace aquaponics, just provide a side avenue to broaden the appeal a little. One of the draw backs to using fish is that some plants need more nutrients than the fish can provide. Using worms will allow for higher concentrations of nutrients than fish can tolerate. Worms may not be something you want to eat, but my tilapia sure do. Worms also sell for $20 a pound, so I can use that money to buy some good feed for the fish.

I am planning on having separate loops in my system. One with fish and one fishless.

Sustainable systems don't run in a straight line. They have lots of branches you need to work with. I like the idea of turning garbage into food.