I bought a house in December last year and have been looking after it since then. When I took over it there was some degradation on the walls, the initial inspector said it was from historic algae staining , but I think it was more degradation marks. It is a quartz plaster pool
The problem I have however is that the walls and floor of the pool seem to have started degrading quite rapidly over the past month. A large number of white splotches (etching?) have appeared on both the floor and wall of the pool, whereas there was no markings on the floor before. In the picture attached see the edge of the pool seat, the seat floor and the wall to the right of the seat for this revealing of the white under layer. The parts mentioned previously that were already stained/slightly degraded last December have gotten much worse and also seem to be degrading at an accelerated rate; see the curved part of the pool wall at the top of the image
As far as I can tell the pool chemistry is fine: the pH, alkalinity and calcium are all at recommended levels. The only thing that is slightly high is the cyanuric acid- 100ppm.
If anyone could offer an opinion as to what could be causing the walls to end up like this it would be much appreciated. Or is the plaster just at the end of its lifespan? (I am not sure when it was last re plastered)