If the CC is only one drop you are fine. That just means the CC is less than 0.5 but more than zero.
Does the staining look anything like this:cottielee said:The water looks beautiful. Clear and sparkling. There does appear to be some slight staining on the walls in the deep end of the pool.
I also noticed my CH is low and my TA is high. I will retest later today because my results differ from the test results at Leslies.
Any advice on what I should do next?