Eli5: How does water freeze and remain clear as glass?


I saw this post earlier: https://www.reddit.com/r/interestingasfuck/comments/c09ntn/ice_skating_on_crystal_clear_ice/
How did this lake froze over with crystal clear ice?

In: Chemistry

by not containing impurities or having excess oxygen content. your tap water freezes cloudy because of the impurities aka minerals that are added or aeration (mixing of oxygen) from the faucet. if you froze distilled water, it would look pretty clear too. then of course, there’s the fact that the water is well lit (aka sunlight) allowing you to see further.

It’s a matter of removing dissolved gases and impurities from the water. You’d want a still lake with low oxygen content. Preferably a lake that froze once and has refrozen.

You might want to go to youtube, and search for “making clear ice”, or check out https://www.youtube.com/watch?v=bUHcCHbgX_o
and you can find techniques to make crystal clear ice for cocktails and the like.