I am trying to garden indoors as organically as possible. Most things I have read say that if you need to raise your PH (make more alkaline), that you add dolomitic or calcitic limestone, or oyster shells. And that if you need to lower the PH (make more acidic), you can add sulfur, peat moss or coffee grounds.
I have some questions about this...
1. Is "dolomitic limestone" organic? Or is it made out of chemicals?
2. Is "sulfur" organic? Sounds a little dangerous lol.
3. Coffee grounds... This one is based on hearsay. Will the coffee end up eventually molding inside the pots? I am a little concerned about this since I live in a high humidity area.
Any other ways to adjust PH without using chemicals?