Can you solve this riddle?

I can be crystal clear but also pitch black. People like me when I am as clear as the fresh air. You can find me just about everywhere besides the desert. I'm very important to have. Any living thing cannot live without me. In very hot places I'm so desirable. I come in jug containers or you can find me running through pipes. What am I?

Click here for the answer

Or Right Click and Copy the Address Below to Share on Forums

URL: