i tried scrubbing it with 2 gallons of white wine vinegar had little effect. Been onto the tech people at K.A. they said if I wanted they would send someone out to do tests for me. After talking to them it sounds like I need to just wait a bit and drop the ph slowly. Doing this quickly using chemicals has the risk once the ph has dropped it might swing back.
Muratic acid would probaly be a better option for something that large. My family owns a masonry company and we use diluted muratic to scrub block. Its available at building supply places like home depot and all used in pools to control ph.
I wouldn't suggest it as a long term solution for your ph but could help neutralize your current situation.
Your other option would be to drain it and seal it with a product like Drylock or Pond armor.
The Drylock is MADE for concrete and is much cheaper then pond armor.