My local Lowes and Home Depot both carry muriatic acid (Kemtek) which is 14.5% HCl, and it's about $10 for two 1-gallon containers:
...and now I just discovered a smaller local hardware store (Do-It Center) carries a different Kemtek box which is 29% HCI and it's also about $10 for two 1-gallon containers!
But before I jump on this, I'm wondering about something. The first one says it contains 8.94 lbs of HCl per gallon. The second one (strangely) says it contains 9.56 lbs of HCl per gallon.
Any chemists care to explain this to me? Is the second box double the strength of the first box (while being the same price)? Or is it only marginally more effective?
Just wondering as I'm always looking for ways to save money. I know I could test this myself by measuring pH before/after using either version, but that'll take several days and I'm just wondering if anyone's got the answer off the top of their head.