Water colour & quality
Did you know pure water appears blue because of its absorption at the red wavelengths and scattering at the blue wavelengths of the visible spectrum?
Pure water has a light blue colour, which becomes a deeper blue as the thickness of the observed sample increases. Any changes from the blue colour is an indication of other material in the water like algae (green) or organic material (brown). Water colour is measured using the Forel-Ule colour scale, which has 21 colours.
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