Stain on my plaster that I've never noticed

[JimFinn]

I'm pretty sure these spots are new. White spots on my tanning ledge.



I started following TFP about 2 weeks ago, so this could be due to anything in the past when I had the pool store taking care of things. When I started TFP, my CH was only at 175, I've got it raised now to about 300. Could it be this, or something else?

 

[ajw22]

White Spotting of New Plaster Pools

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service...

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Plaster Installation and Maintenance - Further Reading

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