Thank you for the bump crazysteve, and the posts you guys.
It would be really awesome to have some sort of larger worm. Then larger fish/turtles could eat it while it cleans the substrate. I am definitely going to look into this further. I feel the closer an aquarium gets to a self sustaining ecosystem the better. Both for coolness factors and the health of the animals. Also, its great to not have to rely on outside people to provide supplies for your pets, in a dream situation. We are already relying on bacteria with the fish to help maintain the system, and many are using plants as well. Why not add in many levels of life forms? Worms, waterbugs, etc.