Turtle Anti-Fungal Block. This anti-fungal block is designed to dissolve when placed into water. Suitable for use with both turtles and fish. It is suggested to use one block per 50L of water. Lasts for up to 7 days, and a new block should be added once the first is almost completely dissolved. The ultimate turtle anti-fungal block contains the following ingredients: Calcium Sulphate, Magnesium Sulphate, Sodium Chloride. Thiamine Hydrochloride (vitamin B1), and Antifungal solution. Pack of two anti-fungal blocks.