Now I've heard that vinegar (organic kitchen acids) works just as good as inorganic acids (HNO3, H2SO4, HCL).
Sombich told me that the vinegar looses its acidity due to breaking down in the soil? I think this is a little bit fetched because the protons will still stay in the soil causing the acidity.
Sombich told me that if you use nitric HNO3, the nitrate ions will contribute as a nitrogen nutrient. But I think adding a few ppm of nitric to get my ph down is not going to do much as a grow nutrient.
Sombich told me that H2SO4 will add sulfate to the soil. I know it's a damn good acid for downing you pH because it's a dual proton acid and kicks in really good. Also, I seem to remember that sulfate is a good trace mineral for the plants.
Sombich told me that HCL (hydrochloric, muriatic) adds chloride ions to the soil and causes it to get salty. I think its no big deal because its only a few ppm to change the pH and that will never cause a significant saltiness to the soil.
I'm using H2SO4. It's a very effective pH down and it's useful to put a little bit of sulfate in the soil. The only proplem is I get my H2SO4 from my lab at my university in a very concentrated form. (one drop in a gallon of water will change your pH by 0.5). You've got to use a pH meter with concentrated acids.
Following the same theory I use NaOH, sodium hydroxide to change the pH towards alkaline if I need it. I actually us the NaOH quite frequently because my nutes make my feed water about 4.5 pH. So I'm constantly raising it.