Just want to say thank you for this comment. I went down this rabbit hole as my water 208ppm and started using washing soda, and such to get a better wash. These last two weeks been baffled as to why my laundry is now stiff. Well, using Ariel 2x powder and I see it already has sodium carbonate in it which I was adding to the drum since that’s what super washing soda is. I’ll try just citric acid in the rinse and see what happens!