Raised calcium hardness and free chloring went to zero

[Yankintx]

Everything was great except my calcium hardness. I added enough to raise ch from 100 to 200, and the free chlorine went from 3 ppm to zero in 1 hour.

Is that common that calcium chloride depletes chlorine?

I since added chlorine but was curious if anyone knew of whether adding the cal. chloride knocks down the fc levels?

 

[chem geek]

Adding calcium chloride should not lower chlorine levels. I've added it with no change in chlorine level. Perhaps the particular calcium chloride you used had contaminants in it.