Gypsum for decreasing PH

[Mustansir Billah]

I have read about gypsum that gypsum decreases PH valve of soil. Gypsum is CaCO3? Plaster of paris(one which is used for building purpose)? So, plaster of paris could be used instead of Gardening Gypsum? If Yes then how much quantity? If NO then what could be added for decreasing PH valve(Anything which is easily available)?

[mikhurram]

This topic has been discussed very comprehensively by Brif Sahib and Newton Sahib. Below is the url of this dicussion.
viewtopic.php?f=13&t=2374&p=24924&hilit=gypsum#p24924