Methylene blue is a synthetic compound with a deep blue color that has been used for over a century in various medical, ...

After much deliberation, I went for the light blue-green shade called ... All that aside, this thing has me drinking more water than truly any bottle or cup I’ve ever had.

and purifies your drinking water in 60 seconds with ... the cap will light up blue. During this time, you should lightly shake the bottle to ensure the UV-C light reaches the entire interior ...