- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
White crystals forming on plaster
- Thread starter voidpointer
- Start date
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Here is the response from my pool builder. As expected they're blaming pool chemistry. How should I respond?
- Jul 21, 2013
- 53,671
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
There is a big difference between calcium nodules caused by delamination and calcium scale caused by high pH. The only thing they have in common is the word calcium.
Your PB needs an education. Send him links to @onBalance articles about Calcium Nodules.
Your PB needs an education. Send him links to @onBalance articles about Calcium Nodules.
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Did you tap around the nodules and listen for a slight hollow sound? Even if no hollow sound is heard, I believe the calcium nodules indicate a plaster problem. There are cracks, but just very difficult to see. The wet look surrounding some nodules indicates a small crack or at least a pinhole. That indicates a defective plaster job.
Therefore, before filling the spa back up, please chisel out a cubic inch of plaster from below the plastic drain in the spa. I will provide an address to send it for analysis. It will cost $50. Other analysis tests may be performed later depending on the results.
Send the PB the same article (Unusual Calcium Nodules) that I linked you to in my first post. Firmly tell the PB that water chemistry does not cause this type of plaster problem, which includes small cracks.
Therefore, before filling the spa back up, please chisel out a cubic inch of plaster from below the plastic drain in the spa. I will provide an address to send it for analysis. It will cost $50. Other analysis tests may be performed later depending on the results.
Send the PB the same article (Unusual Calcium Nodules) that I linked you to in my first post. Firmly tell the PB that water chemistry does not cause this type of plaster problem, which includes small cracks.
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
I forgot to respond to your earlier question on this; sorry. I did tap around the nodules but I didn't notice any audible changes in the sound of the tapping.
Also can you help me understand why I am only seeing this in the spa but not the pool? The same company did the plaster job for both and it was done on the same day, so if there are issues in the spa I'd also expect to see them in the pool.
Spa is filled already but I am happy to drain again to get a sample. A cubic inch is a lot; I'm not sure if the plaster is that thick. I also am not sure how I am supposed to cut the plaster. What tools do you recommend? I do have a chisel if you literally mean chisel with a hammer.
- Jul 21, 2013
- 53,671
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Plaster Installation and Maintenance - Further Reading
www.troublefreepool.com
Calcium Nodules in pools
What are calcium nodules? In swimming pools and spas, they are small mounds, bumps, deposits, or “slag” piles of calcium carbonate which are formed from material that has been released from the plaster. The small calcium nodules are rough to the touch, hard, and generally gritty. Nodules may...
www.troublefreepool.com
Unusual Calcium Nodules
Calcium Nodules In 1998, the onBalance team published a paper in the Journal of the Swimming Pool and Spa Industry (JSPSI) on calcium nodule formation. The paper provided the science and mechanics for the cause of calcium carbonate nodules developing in pools. It explained that delaminated...
www.troublefreepool.com
Focus your builder on the crack that is delamination and has nothing to do with water chemistry.
Why only showing in the spa? Because the spa was plastered separately with a defective batch of plaster.
Last edited:
Yes, a chisel (or screwdriver) and using a hammer. There is a good chance that there is enough plaster below the drain.
The spa has a different batch of plaster and could be different than the several batches in the pool. This type of issue happens often.
The spa has a different batch of plaster and could be different than the several batches in the pool. This type of issue happens often.
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
PB is requesting "current readings of my pool water". What information should I send them? Quite frankly I'm afraid to send them anything because they'll use it against me somehow. On the other hand, if I flat out refuse that doesn't look good either I think.
- Mar 5, 2020
- 3,137
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
No sadly. Fortunately I already keep pH at 7.5-7.8. They weren't very clear on what exact "readings" they wanted either. I'll ask them for clarification.
- Mar 5, 2020
- 3,137
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
He will certainly jump at the frequent pH 8.2 readings. If you had more readings inbetween to show him that you are usually between 7.2 and 7.8, and then added acid once get to or above 8, it would be easier to take water chemistry out of the picture.
Your best bet is probably the sample analysis with an independent expert assessment.
- Jul 21, 2013
- 53,671
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
Oh I don't intend to show them my pool math logs. If that's what you were thinking. He wants CL, pH, and TA. I will send him 7.0, 7.8, and 60. And I guess from now on I'll wait to do the tests until I add MA even though it makes me uncomfortable to do that without testing to see if I need it first.
- Mar 5, 2020
- 3,137
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Which comparator do you have? Only showing 7.8 and 8.2 at the high end? Did you always just call it 8.2 once it was redder than 7.8?
- Mar 5, 2020
- 3,137
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Just test a bit more often (just pH) for a while to show the slow rise until you add acid again. You should not add acid without having tested first.
- Jul 21, 2013
- 53,671
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Test pH first, add acid, test 15 minutes after acid addition, record that value in PM.
- Oct 8, 2020
- 547
- Pool Size
- 19440
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Jandy Aquapure 1400
I have the one from the tf pro kit. I set it to 8.2 when it matches that color. I don't try to guess an in-between. I do wish this pH test had a higher level of granularity
I suggest that the PB is told that your spa does NOT have a typical high pH calcium scaling problem, and therefore has nothing to do with the water balance. But the spa does have nodules that are isolated and random due to a defective plaster problem (the photo of the cracked plaster proves it). Send that photo to the PB and ask him to address the plaster crack and the information contained in my "Nodule" article.