Also, the dry acid (sodium bisulfate), or pH Down or pH Minus, increases sulfates in the water. With Muriatic Acid, one increases chloride levels, or plain salt. There might be some issues if sulfate levels get high, but we don't have enough experience to know at what level things become a real problem (the problems are more theoretical such as very high salt recrystallization with magnesium sulfate that could damage stone and a lowering of the saturation index as well).