Tell your friend to remove the acid bottles from his garage. It will corrode his garage door opener and other metal objects. MA should kept in a plastic box (such as RubberMaid) outdoors and not accessible by children.I wonder if my buddy isn't managing his SW pool correctly then. He is dumping in MA all the time. Or at least he makes it sound this way. I seen like 8 gallons of the stuff in his garage. He's on his 3rd summer with his pool
What is your friends TA level? If it is above 100 (which most pool stores recommend), it will allow pH to rise faster. The TFP recommendation is to have TA in the 60-80 level which reduces pH rise.