Adding Dry Ice to Pool

[chem geek]

Yes, it was fun, but oh so educational...

If anyone wants to do this for Halloween, you could probably get by with 5 pounds of dry ice dropping in chunks when trick-or-treaters arrive. However, if you have lots of guests continually over many hours you'll need at least 10 pounds or more. You must use gloves (leather gloves work great) when handling dry ice as it is very cold and will freeze your skin if you touch it for more than a few seconds eventually leading to frostbite -- not as bad as liquid nitrogen, but not something to fool around with. See this website for lots of great info on dry ice.

Be sure to use a heavy old pan/pot -- thick metal, but not aluminum as the acidity of the water (from the dissolved CO2) might ruin the pan. If you don't want to use a hot plate, then just change the water when it gets cool and refill with hot water (hot tap water is plenty hot enough -- even warm water is OK).

I was actually (briefly) concerned that I was contributing significantly to greenhouse gasses by using dry ice so I did some calculations. Since the body exhales about 200 ml of CO2 every minute, this is about 0.36 grams per minute or about a pound per day. So using 20 pounds of dry ice is equivalent to having 20 people breath for a day. One gallon of gasoline produces around 20 pounds of carbon dioxide so using 20 pounds of dry ice is equivalent to using a gallon of gasoline or driving 20-40 miles depending on your MPG. There, now I've made you feel appropriately guilty, so have some fun and plant a tree (one tree absorbs around 1400 pounds of CO2 over its lifetime, mostly in the first 15 years of its growth).

Richard