CYA over 100 despite using liquid chlorine

[JamesW]

Question remains--how could CYA <40 last November suddenly have become >100 in May, when the only chemicals added to the pool were liquid chlorine and three inch tabs for three short 5 day periods. No dichlor, trichlor or other chemicals added.

How many 3" tabs?

Each tablet adds 1.8 ppm.

33 tabs will add 60 ppm.

Three 5 day periods is 15 days.

You either have test error and/or some type of CYA was added.

It is pretty much as simple as that.

 

[Bperry]

Question remains--how could CYA <40 last November suddenly have become >100 in May, when the only chemicals added to the pool were liquid chlorine and three inch tabs for three short 5 day periods. No dichlor, trichlor or other chemicals added.

The 3 inch tabs have CYA in them. That’s trichlor.