Hard scale deposits? Help

Lykly

Gold Supporter
Nov 6, 2015
889
Ok ok
#1
I noticed upon a week ago what appeared to be a white build up on the side of my pool wall below the skimmer, did not think much of it, but now I'm starting to see a few of them throughout my pool. They appear to be buildup of calcium scale, but they are hard like little rocks I can feel them with my net when I go across them on the bottom scooping up debris. I have always tried to keep my water balance, the pH did get a little high, around eight a couple of times, but nothing too high. I will attach a couple pictures. You may have zoom up you'll see the deposits I am talking about. There are two small deposits right where the trim rock meets the plastered wall on a ledge, the other ones are on the bottom of the pool with the exception of the one right below the skimmer.

Current numbers are:
Ph -7.6
C- 5
CYA-60
CH -600
TA-120
Salt - 3200
Borates - ~30
Temp~70
Water clear
Pool re-plastered about one year ago.

If my pH got a little bit high, I've seen scale precipitate out but never form nodules from the pool surface. Is this a problem with my plaster?






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jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#2
Since these are so localized, it really does not sound (or look) like calcium scaling.

I can not think of the term ............. but I would think that maybe it is from ground water seeping into the pool leaving the deposits behind.

Efflorescence is the term!!! :mrgreen:
 

Lykly

Gold Supporter
Nov 6, 2015
889
Ok ok
#3
Since these are so localized, it really does not sound (or look) like calcium scaling.

I can not think of the term ............. but I would think that maybe it is from ground water seeping into the pool leaving the deposits behind.

Efflorescence is the term!!! :mrgreen:
I know when it was replastered I had some wet spots that were trying to come through as the plaster was drying. If it is ground water precipitating through, is it anything to be concerned about?


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jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#4
Well if water can get in then if the ground water level drop water could get out of your pool too I would think. And you will of course have to deal with seeing and feeling those rough spots but I don't think there's necessarily any danger.
 

Lykly

Gold Supporter
Nov 6, 2015
889
Ok ok
#5
Well it's odd it all just started happening recently. Plus the pool was just re-plastered just now at a year ago. I kind of thought the same thing though as it looks to me like it's coming from the surface rather than out of the water. Is there anything that can be done about it? I wonder if I should call the guy that plastered it, I wouldn't think that should not be happening this soon. The pool prior to plastering, I don't remember seeing any of that and it was many years old. Just replaced because it was etched and not taken care of


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onBalance

TFP Expert
LifeTime Supporter
Jul 25, 2011
871
Utah
#6
The problem may be that they are "calcium nodules" and if you scrape the nodule off, you may see a very small pinhole or crack.
The chemistry of the water is not what causes this type of plaster problem. It is caused by shrinkage cracks and/or delamination.

See this post for more info: Calcium Nodules in pools
 

Lykly

Gold Supporter
Nov 6, 2015
889
Ok ok
#7
Thank you onBalance, what that thread you directed to me describes is exactly what's happening. (at least it describes it perfectly and it was a re-plaster)My question I have for you is do I need to be concerned after I grind them off or just let it be? It does not sound like calling the guy that did my plaster job would be appropriate? If I read your thread correctly, the best thing to do is just grind/sand them off, and possibly have to do it a second time while the water in the void and the pool water equalize and then hopefully not happen again? Or after I grind them off or should I try to Epoxy them?


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onBalance

TFP Expert
LifeTime Supporter
Jul 25, 2011
871
Utah
#8
Actually, calling the plaster guy is may be appropriate because cracking and bonding failure of the new plaster coat is a workmanship issue.
If you are seeing a continual increase in white calcium nodules appearing, that probably indicates a wide spread problem, and perhaps the new plaster coat will soon be breaking away from the substrate.
I doubt you will like that, so I suggest you consider pursuing the warranty on your plaster job.
 

Lykly

Gold Supporter
Nov 6, 2015
889
Ok ok
#9
For what it's worth I did call the plaster guy. He stopped by and looked at it and told me there's nothing to be concerned about. He said since it was a replaster that the spot on the bottom is from a Spike one of his guys were wearing but it would not hurt anything. As far as the scale deposit on the side, there is only one about the size of a dime, he said that I can use a Emory board to remove it. Behind my pool, I have a pretty good little hill and he thinks it could be some of the hard water leaching through. I will tell you that I have a retaining wall with my waterfalls built in it and I have to clean up calcium deposits once or twice a year. Anyway he said there's nothing to be concerned about as far as the plaster bonding to the pool. I tend to believe him. Not much I can do anyway. LOL