White spots..algae or something else?

[jpierce]

Hi all. Needing some help here; not sure what’s going on. Have several areas of “white spots” throughout my pool. Won’t brush off with wire brush. I’ve slammed and brushed for several days thinking it was some type of algae, but not much improvement. Please advise.
What’s interesting is, the white spots are in the same locations where algae usually first appears through the history of the pool.

pH: 7.8
Chlorine 25 (been pouring the Cl to it )
CH: 200
Alk: 80
CYA: 50

 

[jpierce]

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[jpierce]

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[Rancho Cost-a-Lotta]

Have you added any granular chemicals to the pool? Calhypo would do that.

 

[jpierce]

Have you added any granular chemicals to the pool? Calhypo would do that.

Haven’t added any in over a month or so. When I added, i left Polaris running (without bag) to keep circulating because I noticed they weren’t dissolving immediately. Granules were mostly in deep end and not where any of these spots are.

 

[Bperry]

It just looks like bleached plaster, somewhat common in dark plaster finishes.

 

[jpierce]

Certainly not saying you are wrong, but why would this happen now? Been doing the same maintenance routine for years. Granules haven’t been in pool in over a month and the spots aren’t where granules were. These spots are “mostly” on sun deck and on step in deep end. I’m baffled and frustrated.

 

[Rancho Cost-a-Lotta]

i left Polaris running (without bag) to keep circulating because I noticed they weren’t dissolving immediately

Wouldn't the cleaner just pick up the granules and spread them around?

Are the spots raised/rougher than the surrounding plaster?

 

[Bperry]

Certainly not saying you are wrong, but why would this happen now? Been doing the same maintenance routine for years. Granules haven’t been in pool in over a month and the spots aren’t where granules were. These spots are “mostly” on sun deck and on step in deep end. I’m baffled and frustrated.

Don’t know for sure. My parents have had a dark plaster pool for 45 years and it seemed to just happen over time. They just recently replastered so got 40 years out of the first plaster job.