Is sulphuric acid( automotive battery acid) an acceptable way to lower ph. For hydroponic.
No way. That shit is chock full of heavy metals like zinc.
Ugh yeahhhhh not a good idea
Sulfuric acid is composed of oxygen, hydrogen and sulfur. It is fine but use with extreme caution. A little goes a long way. It is over half sulfur by weight. I used one cup per 50 gallons and lowered the pH by 0.1 The oxygen and hydrogen dissipate and the sulfur will remain.