Calcium and Stucco Dust

Jurate1

Active member
Apr 22, 2021
37
Tucson
Pool Size
8000
Surface
Plaster
Chlorine
Liquid Chlorine
Helllo all. Questions on calcium levels. About 2 weeks ago my calcium levels were dropping below 200 so I added some calcium. Levels then up to 300. At the same time we were having some work done on the house. Contractors were filling some cracks in house stucco and doing roofing. I did not have a cover for the pool and did notice some of the dust going in the pool. I tried to skim it off but some had already settled. Anyway my husband tested calcium today and it was 400. I know that is still within normal but I think previous posters had recommended maintaining 300 or 325... CSI today -0.03. Rest of numbers FC 5.5, PH 7.7, TA 50, CYA 40, I know I need to raise Alk a little. Would the dust from the stucco raise the Ca levels? I really did not even think of that...Thanks, Gina
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
43,634
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Would the dust from the stucco raise the Ca levels?
Yes.
Do not raise your TA. Your fill water will do that.
How do you chlorinate your pool water?
Do you use softened water for fill water?
 

Jurate1

Active member
Apr 22, 2021
37
Tucson
Pool Size
8000
Surface
Plaster
Chlorine
Liquid Chlorine
Thanks, I am using liquid chlorine. Average use is about 2 cups a day. I try to maintain FC at 7.0.
The fill water is standard city water...not softened.
I will leave Alk alone as you recommend.
One other thing I forgot to mention is that I just noticed a few days ago a small crack about 5 inches long in the Pebble tech on the pool stairs. Is this something I should worry about or just keep monitoring size of crack?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
43,634
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Great. Monitor the cracks. As long as no leak, it is cosmetic
 

BenB

Gold Supporter
Jul 24, 2020
260
San Jose, CA
Pool Size
19500
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Even in a pool your size though, it would take 7lb of calcium chloride to raise your CH by 100. You said "some" dust and you skimmed it off. You also say that your CH levels were dropping... How would that be happening? CH does not evaporate off.

I think it's more likely to be testing variations than an actual increase.
 

Jurate1

Active member
Apr 22, 2021
37
Tucson
Pool Size
8000
Surface
Plaster
Chlorine
Liquid Chlorine
Thanks Ben you may be right. It could be variation. I was also surprised by drop but we do double check if unusual results. The stucco guys did hook up the hose to the pool drain spigot the first day before I noticed and had them stop. I guess I assumed that the water level dropped a bit then refilled since they used pool water to wash the roof before I intervened. It was probably more then a little dust. They were working on the stucco and roof for a week. They did put plastic down but then when they cleaned up they used a blower before I could stop them and more dust went in the pool. Anyway pool still looks good. I assume the filter and vacumn did their job. I will check Calcium numbers again in a few days. Thanks all for your feedback...
 

BenB

Gold Supporter
Jul 24, 2020
260
San Jose, CA
Pool Size
19500
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Being that you're in AZ and are not using softened water, you should expect CH to rise naturally during the summer as the water evaporates off, and is replaced with water with more calcium in it (the calcium accumulates, does not evaporate with the old water). So to me the puzzle is that it dropped in the first place. Google says Tucson city water is 200ppm hardness, so unless you have a cover over the pool, you can expect your CH to rise very quickly.

Marty who posted before me also has a low-volume desert pool, so he will know more about the rate of increase you can expect, and how often you may need to replace some water to bring it down.