If I were to reduce my CH, currently at ~250 ppm, how would I go about doing this, add TSP? If I were to reduce it, say to 150 ppm, would I be able to tell the difference in feel, i.e. would it feel softer?

Not sure if it's worth messing around with since my water is very clear and all levels are good and stable.

I have an IG vinyl w/SWG.