Canadian Dideuterium monoxide is heavier than the more commonly used Dihydrogen monoxide found in the USA.

http://www.youtube.com/watch?v=hzLs60ZaNW4

http://www.youtube.com/watch?v=YYInVraBe7s

Replacing the Canadian Dideuterium monoxide ice with the more cost effective American Dihydrogen monoxide could even be a solution to save the Polar Bears (due to the global warming) as the lighter American Dihydrogen monoxide ice floats better in the Antarctic Ocean meaning that there is more room for each Polar Bear.