These red & green pellets may be fed to all cold water fish. Formulated at 32% 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.