It is possible that muriatic acid will damage the soil on a permanent basis. If your soil needs additional acid, vinegar works better than anything.
Muriatic Acid
You probably didn't put enough acid in it.
Muriatic acid
If it's calcium then it will foam up if you put straight muriatic acid on it. this wont hurt the tile. however be careful as muriatic acid can be dangerous stuff.
You can get in imediately without worrying about hurting your self.
If muriatic acid has stained black granite, the color of the granite has been removed. This not a stain, it bleached the granite. There is no way to get it out other than to recolor it.
It should work, Try a small test patch before getting over comitted however.
Never put Muriatic into a Well; for any reason. If you want to disinfect your Well; use Chlorine or regular laundry unscented Bleach.
Use muriatic acid to lower your pH. Be mindful of your alkalinity also as the muriatic acid will lower it too. You need both (actually everything in balance) pH 7.2-7.8 Alk 80-120
That Acid is called Muriatic Acid. You put it in your swimming pool to lower the PH of the water. At lower PH Levels, the chlorine you use to sanitize the pool is more active, as a disinfectant. You MUST be careful not to put too MUCH Muriatic Acid in your pool! PH that is too low will create potentially deadly fumes, so test your water. Low pH is corrosive to plaster and metal pool parst.
NEVER put muriatic acid in a well, especially one consumed by humans or animals. Use Chlorine Bleach to kill bacteria in the well. Or call a water professional. They'll probably charge you a couple hundred bucks and use Clorox bleach except it'll be in a plain bottle or aftermarket label.
Well alkalies can be used when acid rain falls on farmland, a limestone powder is put over the field to neutralise the acid.