High ph and Alkalinity trying to find something that works!

I have a new to me pool it is 27,000 gal. I've had pools before just not this big. I was told about the bbb method several years ago by my kids swim teacher and kind of blew it off. She has moved and I have now come back to check it out. I have always had high ph and alkanity. I have added 20 lb of dry acid from Leslie's and 8 lb of ph minus from Walmart. I also in my desperation allowed myself to be talked in to a metal control at Leslie's. I've been floating chlorine pucks and shocking the pool. I can not get any chlorine to register in my pool when I test. My ph has lowered very little and I'm getting frustrated. I tested my pool tonight ph is 8.2+, acid demand is 5 drops, chlorine 0, alkanity 370ppm, total hardness 100ppm, cyanuric acid 0ppm. I am using a test kit I picked up at Walmart. I'm interested in bbb for two reasons. One I live 15 miles from the gas station a pool store is over an hour. Second I vaguely remember the swim teacher telling me she used bbb because she didn't have to lower her ph as much. I'm just at a total loss with this giant 30' round x 52" deep above ground vinyl sand filter pool.
Thank you for any and all help!