do i need to add hardness to my pool?
ch: 25-75 (i'm colorblind and it looks blue to start, maybe a hint of purple)
when i put all of this in pool math, it says my csi is like ~-.8
i was told by the pb that i needed to add hardness, because as water splashes, it has to leach calcium from somewhere. i remember thinking, jeez, wonder if rain waters hard, since as it drains through the sand, it's gonna do the same thing, wonder why they didn't line the outside walls with some kind of tar/vaporbarrier.