Quote Originally Posted by chem geek View Post
You can often buy 15% Muriatic Acid and if you can get it for roughly half the price of 31.45% Muriatic Acid then it's about as economical. I find that this half-strength fumes a LOT less. Nevertheless, my pool store sells the full-strength at the best price so I still use that and am just careful to be up-wind when pouring. I do measure it in a cup, but I do that pouring away from my face and over the pool.

The good news is that though the fumes are irritating, this is actually a good thing since it warns you well in advance of being too harmful. Nevertheless, it's the nastiest stuff most pool owners will experience with regard to chemicals.
It has been my experience here in Arizona that the full strength (31.45%) Muriatic acid is sold almost exclusively by pool stores, while the Grocery stores and Hardware stores sell the 15% strengths. It is also my experience that both strengths are not that far apart in price.