I have recently switched from dry acid to muriatic acid for PH control in my pool. A person who has maintained the "High School Pool" here in my town (Homer, AK) told me that the Borough School District changed from MA to Acid Magic several years ago. I looked it up and it seems that the price of AM is at least double, or triple for what I pay for MA in my area. I have an indoor pool but just mix up the MA in a 5-gallon bucket with water outside and bring it in to mix with the pool water. Works great. Maybe the Gov-Mint thinks that MA is "dangerous?" Or is MA really better? Any thoughts?