I'm working on lowering my TA in order to add Borax to my water. It was quite high at 130. I added acid and it is now down to 90. I'm aerating it right now and plan to add more muriatic acid to continue to lower it. How low should I take it in order to be able to add the Borax and not raise the TA too much. I'd like to keep it on the low side since the TA of my refill water is very high.