Is this etched plaster or calcium deposits (or both?)

[stevenl241]

Hi
Big fan of TFP and really appreciate all of the expert advice here.
Trying to decide whether to raise CH before closing?
But I'm not sure what I am seeing.....

The pool surface is quite rough - like sandpaper.
This pic is the top step surface from the beginning of the season.
Is this a plaster surface that has been damaged by etching?
Or is this a plaster surface that has been damaged by calcium scaling?
Or both?

The whitish areas seem a little smoother than the slightly darker areas, but do not seem to be raised above the surface of the plaster.

I assumed it was calcium deposits, so kept the CH a bit lower (150) - but managed the pH to keep the CSI close to zero. Over the season some of the whitish areas have disappeared.
But the pool surface is still rough.
Never seen a new plaster pool so I'm not sure what I should be seeing.

Thanks for any advice.
Steve


FC 5.4
CC 0.0
CH 150
TA 100
pH 7.8
CYA 30

 

[xyz]

My plaster pool, after it was acid washed, was smooth and white. By smooth I mean if your hand is wet, it would slide over it with no discernible friction or rough feel.

 

[duraleigh]

Calcium deposits are caused by pH too high. Plaster etching by pH too low.....both over a long period. Do you have any idea whether your pH was high or low? (Not overnight, either......this would have to be weeks and likely months or years)