I have been lowering my TA over the past few days. It started at ~ 150 and now is near 90 ppm. I have been using up my dry acid and starting to use muriatic aliong with aeration. My last slug of muriatic was ~ 18 hours ago, dropping the pH to ~ 7.0. Despite continuing to aerate for ~ 18 hours, the pH this time has only increased to ~ 7.3 or so. Usually, it would only take about 6 hours at the most. That is to say, the correction of pH using aeration is much slower this time despite having a lower TA (buffer).
Is it time to give up on the aeration? If need be, should further pH correction be done with Borax?