Strange Calcium Build up and CYA challenge

Dgreen

Member
Jul 23, 2022
18
Austin
I have a calcium buildup around the negative edge spa. A wire brush did not work. My plan is to drain the pool a few feet and try CLR. Calcium crystals only show up in spa. Any suggestions about how to best treat this?

Also I have been mostly using TFP protocols and recommended test kits for a year. I was traveling a fair amount and I used Chorine Tabs over the summer and it drove my CYA from 40 to 100. My understanding is I have to completely drain the entire pool to fix CYA and avoid tabs like the plague. We have a drought in Austin, so I have not done this yet. Since it is over 108 degrees in Austin and "an area with 90+ pool water temperatures and extreme sunlight exposure 10+ ppm of CYA a month can be lost through degradation," I am considering waiting and seeing if it will drop. Is this a bad idea to wait?

Test kit I use a Taylor 2006c.
In-ground 10K gallon pool plaster pool in Austin, TX
FC 10
PH 7
TA 140
CH 400
CYA 100
CSI .17
Pool temp 95 Degrees
Air temp 108 degree
 

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That is Efflorescence - Further Reading

It has nothing to do with your water chemistry.

Water is finding its way into the gunite and out those area.

CLR will not make a dent in it. You need to scrape it off and use a muriatic acid solution to soften it.

Keep your FC up while you wait for your CYA to degrade.

Note that your pH is invalid when FC is over to. I am concerned about your pH being at 7. The tablets crashed your pH. Stop using the tablets and check your pH when your FC is below 10. Your pH should rise with a TA of 140.
 
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Allen, Thank you for explaining its Efflorescence, and I will keep my FC at 13 unless you suggest I stay higher. Yes, I am done with tablets.

Since CYA is so high, I believe my TA reading may not be accurate. I will also turn on the aqua accent water features to aerate the water to help drive PA up and test when FC drops below 10.
I will try acid to clean it with a wire brush and see if that works. I am not sure how to do this safely because the acid is so intense to work with. Is the Efflorescence bad for the pool in any way or is it just an eyesore?

 
High CYA does not effect TA.

Efflorescence is just a cosmetic problem.
 
Does this mean that pool was not sealed properly by the spa (the pool is less than 2 yrs old)?
The grout or mortar around the joints where you see the efflorescence have small cracks letting water in.
 
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