Color of water

The hue of water is an intrinsic property and is caused by selective absorption and scattering of blue light.

[3] The absorption curve for heavy water (D2O) is of a similar shape, but is shifted further towards the infrared end of the spectrum, because the vibrational transitions have a lower energy.

For this reason, the pipe needs to have a length of a meter or more and the water must be purified by microfiltration to remove any particles that could produce Mie scattering.

This contribution usually makes the body of water appear more a shade of azure rather than cyan depending on how bright the sky is.

The relative contribution of reflected skylight and the light scattered back from the depths is strongly dependent on observation angle.

[8] Scattering from suspended particles also plays an important role in the color of lakes and oceans, causing the water to look greener or bluer in different areas.

Because most lakes and oceans contain suspended living matter and mineral particles, light from above is scattered and some of it is reflected upwards.

[9][10] Diffuse sky radiation due to Rayleigh scattering in the atmosphere along one's line of sight gives distant objects a cyan or light azure tint.

In glaciers, on the other hand, the pressure causes the air bubbles, trapped in the accumulated snow, to be squeezed out increasing the density of the created ice.

Blue can also indicate copper, or might be caused by syphoning of industrial cleaners in the tank of commodes, commonly known as backflowing.

This usually has a strong sulfur or rotten egg (H2S) odor and is easily corrected by draining the water heater and increasing the temperature to 49 °C (120 °F) or higher.

[citation needed] Learning the water impurity indication color spectrum can make identifying and solving cosmetic, bacteriological and chemical problems easier.

[14] Color from dissolved substances is not removed by typical water filters; however the use of coagulants may succeed in trapping the color-causing compounds within the resulting precipitate.

a glass of transparent water sitting on a wooden table
When water is in small quantities (e.g. in a glass) it appears colorless to the human eye .
An indoor swimming pool appears cyan from above, as light reflecting from the bottom of the pool travels through enough water that its red component is absorbed. The same water in a smaller bucket looks only slightly cyan, [ 1 ] and observing the water at close range makes it appear colorless to the naked eye.
High concentrations of dissolved lime give the water of Havasu Falls a cyan color.
Glacial rock flour makes New Zealand's Lake Pukaki a lighter turquoise than its neighbors.
Red tide off the California coast