Bitter grass is a common aquatic plant, which is also called noodle grass. Its leaves are long and narrow and look like kelp. They have strong adaptability to water quality, like to live in slightly alkaline water, don't like high temperature, and are cold-resistant, which is similar to Koi's habits.

Euleropsis curularis is slightly larger in size, but its leaves grow upward in a rotating way. It looks like rows of waves, which is very beautiful. They like light, but they don't like high temperature. The most suitable water temperature for their growth is 24 ℃. Their leaves are large and rotational, so it is difficult for koi to chew them off.

Crown grass has large petioles, wide leaves and more plant height over 60 cm, which is a very gorgeous large aquatic plant. They are suitable for living in neutral water, but the water temperature should be above 24 ℃. Because the leaves are very large, it is difficult for koi to bite and it is safer to put them together.

Pocket crown is relatively small in size, and its leaf length is generally about 3-5 cm. They don't require high temperature, and they can survive at the water temperature between 18-28 ℃, which is as wide-temperature as koi fish, but they need to supplement iron fertilizer to grow better. If you want to raise it with koi, try to use decorations to separate it, otherwise it may be eaten by koi.