This is all new water. This is an intex pool that you have to take down in the winter. I have been adding a cup a acid to lower ph and then aerating for about 2 weeks now, but my ph was only going to around 7.5 Then we tried 1 and half cups of acid, but the ph is still not going lower than 7.2. Do you think I can add 2 cups of acid and then aerate?