I will take duckweed from my guppy tanks and I will put them into my goldfish tanks for the Goldfish to eat and I will take Guppies from The Guppy tanks and put those into my snapping turtle tanks for my snapping turtles to eat basically the guppy duckweed tanks are a food producing tank the Guppies get fed with fish feed and the Guppies grow and multiply and that provides protein enrichment source for the predatory snapping turtles and then the poop they produce actually grows duckweed with the