Scale

[Sausage]

Hi,
I have an inground plaster pool that is about a year old. There is a hot tub attached with a spillover that runs about 18 hours per day. The hot tub continues to form a white line of scale at the waters edge, yet the pool itself has no scale. Anyone know why? Is it the heat?

PH: 7.8
FC: 3
CC:0
TA: 70
CyA: 60

 

[JasonLion]

Yes, it is most likely the heat. Calcium is more likely to deposit at higher temperatures.

Also, you should post a CH level. That will tell us a little more about what is happening.