I couldn't find MA at Lowes today so I grabbed PH Down which is Sodium Bisulfate. I've never had to lower my PH, it is at 7.8 right now. Usually I start the season off a little low and with areation and the kids splashing around it is up to where I want it in no time. According to the label I should use 7 oz per 12,500 gallons which is about what my pool is to get it from 7.8 to 7.6. Is this ok to use or should I take it back and find MA. I don't anticipate it's something I'll need regularly. For the past two seasons I've only needed bleach the entire time. I replaced a lot of water this year though and did need to add CYA to get me from 20 to 30 so I wasn't sure if this had anything to do with it.