Hi all,
I'm located in the northeast and I had a gunite salt water 18x36 free form pool installed and ready for swim in late August 2015. It has a dark grey plaster finish. Last year we had no problems. I took the cover off this year and this is what I discovered. I've brought these pics to the local expert pool place and 3 of them said they've never seen this before. I brushed on some 50/50 MA mix and it foamed up so I believe it's calcium build up of some sort. The pool guy didn't understand how this could be because the calcium readout was almost zero. I tried brushing with a wire brush and the stuff just barely comes off. It feels like 60 grit sandpaper. The pic labeled pool step is of the sun shelf that was not underwater during the winter compared to the greenish brown step that was underwater. The entire pool looks to be coated with this stuff. My test results are PH: 8.6, hardness: 45, TDS: 1400, Free Chlorine: 0.1, Total chlorine: 0.1, CYA: 5, Optimizer plus: 2. Any ideas on what this is, how to prevent it, and how to remove it would be much appreciated.
I'm located in the northeast and I had a gunite salt water 18x36 free form pool installed and ready for swim in late August 2015. It has a dark grey plaster finish. Last year we had no problems. I took the cover off this year and this is what I discovered. I've brought these pics to the local expert pool place and 3 of them said they've never seen this before. I brushed on some 50/50 MA mix and it foamed up so I believe it's calcium build up of some sort. The pool guy didn't understand how this could be because the calcium readout was almost zero. I tried brushing with a wire brush and the stuff just barely comes off. It feels like 60 grit sandpaper. The pic labeled pool step is of the sun shelf that was not underwater during the winter compared to the greenish brown step that was underwater. The entire pool looks to be coated with this stuff. My test results are PH: 8.6, hardness: 45, TDS: 1400, Free Chlorine: 0.1, Total chlorine: 0.1, CYA: 5, Optimizer plus: 2. Any ideas on what this is, how to prevent it, and how to remove it would be much appreciated.