When I add 1g gypsum, 2g calcium chloride, 1g epsom salt and 1g of chalk, I get RA : 38 (which seems very low) and pH 5.50.
If I want a RA of 200, I have to put 2.5g calcium chloride, 3g epsom salt, 4g baking soda and 4g of Chalk. It gives me RA : 200 and pH 5.65
Whatever I do to reduce my pH...