can you put dry ice in a pool to cool it off
Yes, for an outdoor pool in small amounts but it is not SAFE for an indoor pool or spa with poor ventilation system in an enclosed space.
Dry ice is a carbon dioxide when it is solid and it can lower your pH quite largely, causing some serious water balance issues. Personally, I would recommend not adding it to your pool even if it is perfect for Halloween or a pool party.
Can You Put Dry Ice in a Pool to Cool it Off?
Small amounts of dry ice can be added to a pool (in an open space) in small amounts to make it cooler.
Adding more to a spa or pool will greatly reduce the PH levels and could very well cause damage to the equipment. Adding even as little as 1 pound of dry ice to a 350-gallon spa can significantly bring the PH to 5.5 and ten pounds to 4.6.
Warning: When using this stuff in an enclosed space, be very careful with it. Carbon Dioxide is pretty toxic, at lower than you would expect levels. A little bit as party favours isn’t a big deal, but when you are throwing 60 lb blocks into hot water, then sticking your face in the vapour, you could suffocate.
Dangers of Using Dry Ice in a Pool
Personally, I have noticed that dry ice tends to sink to the bottom. I am concerned dry chunks of ice will settle down and sit on the plaster where it will locally cool the spot. I was worried that this would create small hairline cracks from the thermal expansion differences.
The way I went around this is to rig up some course mesh bags to hold the dry ice in and then suspended them from pool noodles. This lets them to float around a bit.
Other problems include:
Just don’t allow people touch it. It could lead to frostbite burns.
Also, liquid dry ice is that carbon dioxide and it is heavier than air. So, if the pool were in a recessed area the carbon dioxide could be “pool” displacing the air (and hence the oxygen in it). Thus swimmers could suffocate