Hello Saludos
Here is what it says in my book Hydroponic Home Food Gardens by Howard M. Rush about pH adjustment:
The pH of the
nutrient solution can be raised ( made more basic ) by use of potassium hydroxide (KOH), sodium hydroxide (NaOH), or bicarbonate of soda (NaHCO3). The latter is safest to use; the first two burn the skin.
Great caution must be observed, and goggles and rubber gloves must be worn when using the hydroxides (the first two compounds mentioned above). Carefully observe all of the cautions suggested by the manufacturer. The addition of small amounts (several grams) will quickly shift the pH of the nutrient solution toward basic.
A basic solution is lowered ( made more acidic ) by addition of sulfuric acid (H2SO4)-battery acid; nitric acid (HNO3); hydrochloric acid (HC1)-muriatic acid, sometimes used to treat swimming pools; or acetic acid, such as vinegar.
The best acid to use, from the standpoint of simple effectiveness, is sulfuric acid, but it is especially corrosive and-as with nitric acid and hydrochloric acid-burns the skin. So again, rubber gloves and goggles must be worn to prevent injury to hands and eyes.
After reading that, hydroponics don't seem like so much fun any more does it. That is why I pay 30 dollars a gallon for pH up and down from a hydroponic grow store. I don't know what they use but you don't have to wear gloves and goggles.
Ron