Fry Cradle is a sustainable fish fry-rearing system that leverages the interactions between fish fry, biofloc, Tubifex worms, and rotifers. It addresses fish waste disposal and fry sensitivity to water quality changes. Fry Cradle uses biofloc to process fish waste, reducing ammonia and nitrite levels. Tubifex worms feed on fish waste and serve as food for the fry. The system uses RAS technology to monitor water temperature and ammonia concentration, ensuring optimal growth conditions. Fry Cradle creates a sustainable cycle, purifying water and reducing labor and feed costs for fish farmers.