I have been trying to determine if the discoloration of our new pool (filled last September) is due to staining or a fault in the plaster. The discoloration has been present pretty much since the beginning. Of course the pool builder says it must be due to water balance, metals, etc. Anything but the plaster.
The surface is Quartzscapes Aruba Sky. The staining is dark blue and is most prevalent on the horizontal surfaces - floor and steps - and creeps up the sides to a point and then stops. From the pictures I've found, I was sure it was a copper stain, even though I don't know where the copper would be coming from other than the source water. I don't have a heater or any copper piping and I've never used an algaecide.
I tried rubbing vitamin C tablets and poring muriatic acid down a pvc pipe onto the stain (in different areas) and both actually made the stain darker. Now I don't know what I am dealing with. I have a salt water pool so I don't have any chlorine tablets to try, but it doesn't look organic.
Current conditions are:
Water crystal clear and always has been
The CH stayed steady for the first few months at about 280, but has been rising steadily since March. The TA rose at the same time to about 120 before I was able to get it back down. The pH has at times gotten past me and risen to 8.2. I have to add acid every day to keep it down but I haven't always been able to do so. I am sure the high pH and the high CH at least contributed to the problem.
What else can I try to help me determine what is causing this?