Quote Originally Posted by chemicalbalance
Acid lowers pH and and only lowers alkalinity temporarily (sort of).
That's not completely correct. For those who might be confused, here's the quickie answer: Lowering your pH down to the 7.0 range will result in some permanent reduction in alk, due to offgassing of co2 during the low pH period. If you can areate the water to offgass more co2 while your pH is low, your alk will drop even more. Simply put, acid WILL permanently lower your ALK, if you drop it low enough.

Michael