Matt333

Hi guys, I need help with a question. I have a pool with a volume of 120,000L. Its pH is currently at 8.2 and I need to lower it to 7.5 using muriatic (hydrochloric) acid with a concentration of 9M. How many litres of hydrochloric acid do I need to add? I've been given a table that lists the different amounts of HCl needed for different volumes of water but I'd like to know the steps behind calculating it. (Table recommends ~2.3L for a 120,000L pool) Thank you in advance, Matt