The blue of platinum blue pool should not be a metal ion solution that many people say. First of all, the most widely circulated here is aluminum hydroxide solution. If I remember correctly, the aluminum ion is colorless and the aluminum hydroxide is unstable...Blue is more common in copper ions, but if it is a metal ion solution, It should be blue no matter how much, observe the surrounding water, and find more still water showing this deep blue. Therefore, the cause here should be closer to the Jade Dragon Snow Mountain Blue Moon Valley, Banff, Canada, belonging to the melting water of glaciers to form a lake, the water is clear, but the impact carries small gravel invisible to the naked eye, quiet water because of the Dingdar effect to form this kind of glacial lake unique blue. Jiuzhaigou is different from here is calcium, which is an important evidence of dissolving metal salts in water, so Jiuzhaigou color is a more complex superposition factor, and the color is more abundant, so there is no more description here.