Mash/Sparge pH Acids

There are 2 types of acid that can be used to lower sparge water or mash pH, 88% lactic acid, and 10% phosphoric acid. 

Lactic Acid - 88% concentration - 4oz or 16oz bottle
Can be used to lower pH of mash/sparge water. Widely used as an acidulant for preservation and flavor enhancement. Perfect for lowering your PH, ideal to use when brewing Sour Beers.  88% concentrate. 

Phosphoric Acid - 10% concentration - 8oz bottle
Phosphoric acid is said to be tasteless while lactic in large quantities can potentially leave flavor. Being a lower concentration than the Lactic, it is slower to change the pH of your water and therefore more forgiving to use. Also more stable at higher temperatures.