These red & green pellets may be fed to all cold water fish. Formulated at 35% protein and completely balanced for beautiful, colorful fish. The pellets come in 5 different sizes 1 & 2mm pellets for koi up to 10cm, 3mm pellets for koi up to 20cm, 4mm pellets for koi up to 30cm, 5mm pellets for koi larger than 30cm.