New dark plaster having white spots

Fugazi

Well-known member
Apr 9, 2015
64
Saint Augustine Fl
I had my pool refinished with a black finish over thanksgiving and slowly the pool finish is having white streaks
I put the anti scale agent every 3 weeks and I followed the instructions from the pool folks who did the install.

However they are advising me since the pool is new that PH 7.6 is to high and to keep it at 7.2

I check my water 2 times a week and it’s around 7.5-7.6 and everything else is normal


Here are the feb numbers
Where there is an x I didn’t perform the test


2/4
6.5 chlorine
325 calcium
90 Ta
45 cya
7.8 ph

2/7
5.5
X
90
X
7.5

2/11
6
275
80
X
7.6

2/14
4.5
X
70
X
7.6

Would the PH really have an impact on scaling? And if so is my ph to high?89672146-DDF2-4AFF-B728-FFCB2D4E0E76.jpeg
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,750
Laughlin, NV
pH has a significant impact on scaling - see Pool School - Calcium Scaling

However, a number of posts on this forum have shown that dark plaster has extensive 'mottling' and is subject to noticeable imperfections.

From your tests I do not see an issue with your CSI. Do you track that parameter? It is calculated in PoolMath and in the App.

Take care.
 

Fugazi

Well-known member
Apr 9, 2015
64
Saint Augustine Fl
pH has a significant impact on scaling - see Pool School - Calcium Scaling

However, a number of posts on this forum have shown that dark plaster has extensive 'mottling' and is subject to noticeable imperfections.

From your tests I do not see an issue with your CSI. Do you track that parameter? It is calculated in PoolMath and in the App.

Take care.

I am inputting the test values from the pool kit from troublefreepool store and entering them in the poolmath website

I do my tests on Wednesday and Saturday/Sunday

I scrub the pool floor and walls twice a week
I vacuum the pool on the weekend and clean he filter on the weekend
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,750
Laughlin, NV
With new plaster you should be testing pH every day. That way your pH does not swing high/low/high.

- - - Updated - - -

How do you chlorinate?
 

Fugazi

Well-known member
Apr 9, 2015
64
Saint Augustine Fl
With new plaster you should be testing pH every day. That way your pH does not swing high/low/high.

- - - Updated - - -

How do you chlorinate?
I tested the pool every day for the first month

But looking at my data is it swinging wildly?

I am using liquid chlorine to reach the level recommended by the poolmath and I have a puck and it’s set at 1.5

I can start testing the ph daily and see how much it’s changing
 

jeffchap

Bronze Supporter
TFP Guide
Jun 26, 2012
1,760
Edmond OK
My pool is fairly dark and when I purchased it, it had a good number of white spots (or small white nodules) all over the bottom and sides. There were also some white streaks similar to what I see in your picture.





On a whim, I picked up a potato shaped pumice looking rock from the flower bed and tried scraping off one of the spots. It worked great, and didn't leave any marks on the pool itself. So my OCD kicked in and I spent the next several evenings scraping every spot and streak off that I could reach (I'm going to need some scuba gear to finish the job). But I'd guess that 90% of all the white came off and it looks much better now.





From what I've read, these spots are due to calcium from the surrounding soil leaching back through imperfections into the pool. Your problem may not be the same, but I thought I'd throw this out there as something to try.
 

Fugazi

Well-known member
Apr 9, 2015
64
Saint Augustine Fl
The company that plastered my pool said the stucco dealer looked at the photos and said the following

“calcium Scale Plated Out, hit it with the Jacks Number 2 treatment, but wait until the water warms up or it won't work".

I am dumbfounded tho as the CH was at or below 325. And ph within normal levels

I am wary of draining and acid wash since I don’t know how to prevent it again.

I was thinking of lowering ph to 6.8
Then use steel brush alongside pulmice stone to remove scaling

Is that idea sound?