2 Teaspoons battery acid for 5 gallons water is working out real well. brings ph from 8.2 down to 6.1- 6.3.
Got some rubber gloves and popped the caps and drained then into a plastic pail then carefully poured them into 2 litter bottles..
I have access to old batteries, and it seems to stabilize my ph a lot better.
One plant likes it sour the other sweet. I would say just keep em happy.