Coffee beans(spent), tea leaves(spent), elemental sulfer(slow), magnesium sulphate, sulphates of any kind(chemicals shop ask for industrial grade not pharma or food. Cost difference.), vinegar diluted table spoon to a gallon of water, sulfuric acid diluted(careful). Calcium carbonate reacts with acid to make carbonic acid which is vented leaving behind salts. Calcium salt for one. It has been a long time since I did chemistry but do look up Humic acid and you will find what salts are left behind. Salts, these plants hate.
Why not grow them in the medium they were found in?
Regards,
Arif.
