Why is the water in Jiuzhaigou so rich in colors? Is it because filters have been added?

Haha, of course not! The water colors in Jiuzhaigou come from calcified sediments, algae, and mineral refraction. Take Wuhuahai (Five-Flower Lake) as an example. At the bottom of the lake, there are "tufa" formations created by the deposition of calcium carbonate. When sunlight penetrates through water layers of different depths, combined with the reflections of the surrounding vegetation, it presents a magical blend of blue and green hues.