eli5: Why is water clear in small quantities but blue when in large quantities?

Question

eli5: Why is water clear in small quantities but blue when in large quantities?

In: 3

Answer 1

Saturation, basically. When there’s not a lot of water, we can mostly see entirely through it. The more water you stack up, the less we can see through and the more of the water’s color (or, much more commonly, the color of the things in the water) we see, until at some point enough of the light is blocked from coming back to our eyes that we can’t see anything but the color.