Hikari Turtle Sticks are a mix of three different coloured sticks, each containing essential nutrients, providing complete and balanced nutrition for Aquatic Turtles Yellow Stick - Staple nutrition, containing the highest quality proteins, minerals and multi-vitamins to promote proper growth and help keep turtles in peak condition Green Stick - Calcium enriched stick supports shell development and structure whilst helping prevent disease caused by calcium deficiency Red Stick - Conditioning stick, containing Chitosan extracted from crustaceans, to support metabolism, immune system health and skin resiliency Hikari Turtle Sticks are easily digested, reducing water quality problems and odour that can result from uneaten or partially digested food, and quickly absorb water and softens rapidly while retaining its original shape.