NorthFin Koi Supreme Formula Premium Fish Food. NorthFin’s Koi Supreme formula offers your Koi which are omnivore fish, a complete and highly nutritional diet that allows the Koi to rapidly grow and develop vibrant colours. It’s supreme formulation ensures your Koi maintain their vitality and health while keeping your pond cleaner for longer periods. Available pellet size : 4 mm, 6 mm Pellet type : Floating pellets Recommended for : All types of Koi fish and large non-Fancy Goldfish Available Sizes: 4 mm (250 g, 500 g, 1 kg, 2.5 kg) 6 mm (250 g, 500 g, 1 kg, 2.5 kg)