I've read some posts that suggest adding a product called Gentle Spa to make the water feel silkier. I also read that adding 20 Mule Team Borax and muriatic acid at the same time will do the same the thing. if that's correct, I'd rather do the latter since I already have those on hand.
The question is how much to add and how to do it? What number do I input in the "Target" column in PoolMath? Is it safe to mix the two products together in a bucket before adding, or do I add one to the spa after another?