Does anyone know if Muriatic Acid loses its potency? I am using 31.45% but seem to be having a SLOW time lowering my TA in my 350 gal Hot Springs spa. Did a refill today after using Ah-some. TA is very high in our well water -300 to start and I've been working on lowering it for the past 4.5 hours. So far I've used 22.5 oz to get TA to 130. My goal is 80 for TA. Last time I had to use a little over 24 oz to get TA to 80. Any thoughts if acid loses its strength? What do you think the maximum amount of MA that could be added at each 30 minute interval? I've checked the pH about 5 minutes after adding the MA and it's still 8.0