It's been a long time since I've posted anything in the forums thanks to being a BBB person for the last 10 years or so. However, I am in the middle of bringing my numbers back up after treating for metal stains with ascorbic acid and I have a question. My current alkalinity is sitting at 70 and the Pool Math app says the target is 50-90. In the past my target has always been higher (a lot of places say 120 is a minimum). So....should I switch from baking soda to Borax now to raise my pH some more and leave my alkalinity at 70 or should I continue to use baking soda to raise both pH and alkalinity?