Borates and PebbleTec Recommendations

[MSDalton]

First let me thank you all for helping my family enjoy our pool!

I'm considering adding Borates to my pool to try and get more pH stabilization and have several questions.

Background

Chemistry	pH	TA	CH	CYA	CSI	FC
My Pool	7.7	60	400	40	-0.06	4
PebbleTec (PTI) Rec.	7.2 - 7.6	70 - 100	150 - 300	20 - 30	-0.3 - 0.3	1 - 3

Historically, after 6-years my pool had drastic calcium nodules. My pool builder warrantied the job and in June 2020 removed the old plaster and replaced it with a PebbleTec (PTI) PebbleFina finish. Having had such a bad experience, I am very motivated to maintain this finish!

I use Pool Math 100% of the time (I love that I can click on the CSI "tab" in the "Overview" and play with the numbers and see what effect any/all changes will have on CSI before I do them!). I use a Taylor K-2006C FAS-DPD test kit. I use liquid chlorine.

My goal is to honor the PTI recommendations as much as possible (warranty). I decided to bump my CH above the PTI recommendation in order to give myself more wiggle room on pH and TA and still consistently keep CSI between -0.3 - 0.3. The problem I'm running into is that I cannot stabilize pH at 7.6 and TA at 70 at the same time. Therefore, I'm considering adding borates. All feedback is more than welcomed!

Questions

1. I use CSI as the main driver for my chemistry. Is this correct?
2. Does Pool Math automatically correct TA & CSI for Borates?
3. After adding boric acid, should I expect to (a) be able to stabilize my water closer to pH 7.6 and TA 70, (b) be able to lower my CH, and (c) maintain balance better?
4. Am I right in thinking that the right borate conc. would be 30-ppm?

Thanks for any / all help.

Mark

 

[Ripple]

I am interested in this thread as I also have a PebbleTec finish. I noticed the recommended values you listed are for PebbleTec are slightly different than what I see on their website. Perhaps I am overlooking something?

• pH: 7.2 to 7.6
• Free Chlorine: 2 to 4 ppm
• Total Chlorine: No higher than the Free Chlorine
• Total alkalinity: 80 to 120 ppm
• Calcium hardness: 200-400 ppm
• Cyanuric acid: 30-50 ppm

Chemicals Keep Your Pebble Tec® Pool Surface Clean All Summer Long

Even though it looks complicated, keeping your pool’s chemical levels balanced is simple. Learn how chemicals keep your pool surface clean and water clear.

www.pebbletec.com

 

[MSDalton]

I am interested in this thread as I also have a PebbleTec finish. I noticed the recommended values you listed are for PebbleTec are slightly different than what I see on their website. Perhaps I am overlooking something?

• pH: 7.2 to 7.6
• Free Chlorine: 2 to 4 ppm
• Total Chlorine: No higher than the Free Chlorine
• Total alkalinity: 80 to 120 ppm
• Calcium hardness: 200-400 ppm
• Cyanuric acid: 30-50 ppm

Chemicals Keep Your Pebble Tec® Pool Surface Clean All Summer Long

Even though it looks complicated, keeping your pool’s chemical levels balanced is simple. Learn how chemicals keep your pool surface clean and water clear.

www.pebbletec.com

Thanks much for the reply. I was going by information provided to me by the PebbleTec installer. The numbers you provided (from the PTI website) give me even more interest in trying to stabilize pH and TA within these ranges. I'm very interested in learning whether the chemistry experts believe that adding borates would likely allow me to approach the PTI TA minimum (80 ppm) while simultaneously maintaining pH at 7.6. With the caveat that my PTI finish is only 3.5-months old, right now I don't see this happening without some help. Thanks again.