Problem
Almost the entire surface of my gunite/plaster pool (redone ~2 years ago) feels like sand paper. Parts of the walls feel partway to barnacles (exaggerating a bit). The highest step feels relatively smooth. Kiddos are scraping their feet and knees when playing and I’m getting a little worked up about it if I’m honest. Costly purchase, gone wrong?!?!
I’d love some help determining a specific roadmap of steps to take and roughly when to take them.
My thought is to keep the pH (and CSI) pretty low for a couple months and if things don’t improve, drain and sand it down in September.
Chemistry History
You can see my pool math readings for this year, when I learned about you all! Historically, I tried hard to keep what I understood at the time (which has now changed) as good chlorine: 1-3ppm and pH levels: mid 7s. I ALWAYS struggled to keep pH down putting in what felt like a lot of acid. I tested pH, chlorine, and salt myself (Taylor but not FAS-DPD). I checked in with the pool store for the alkalinity, calcium hardness, CYA, but only adjusted for CYA. I’ve learned the error of my ways.
The pool was closed 9/30/2023 and I opened 4/28/2024
Measurement at Opening (no closing measurement
)
pH: 8+ (8.6 according to pool store…I know…)
Cl: 0
Current Measurement
FC: 5 (bringing it back up)
pH: 7.4
TA: 40
CH: 340
CYA: 50
My Guess
The pH was too high and calcium scale (of some form) began to appear.
What I’ve Done
Specific Questions:
More Context
I’m a pretty new/novice pool owner (1.5 seasons). I “maintained” the pool over this winter and opened myself for the first time. Unfortunately, by “maintenance” I mean I did nothing. If I’m honest, pool chemistry over the winter didn’t even cross my mind, it does now. I’ve been learning by reading online, followed by trial and what feels like a big error. I brushed heavily as instructed for the first summer and continued brushing at least weekly last year. As mentioned previously, I tested and balanced regularly (as best I knew at the time). Since finding TFP I’m using the FAS-DPD and testing almost daily and feel much more confident about the chemistry I’m maintaining.
Almost the entire surface of my gunite/plaster pool (redone ~2 years ago) feels like sand paper. Parts of the walls feel partway to barnacles (exaggerating a bit). The highest step feels relatively smooth. Kiddos are scraping their feet and knees when playing and I’m getting a little worked up about it if I’m honest. Costly purchase, gone wrong?!?!
I’d love some help determining a specific roadmap of steps to take and roughly when to take them.
My thought is to keep the pH (and CSI) pretty low for a couple months and if things don’t improve, drain and sand it down in September.
Chemistry History
You can see my pool math readings for this year, when I learned about you all! Historically, I tried hard to keep what I understood at the time (which has now changed) as good chlorine: 1-3ppm and pH levels: mid 7s. I ALWAYS struggled to keep pH down putting in what felt like a lot of acid. I tested pH, chlorine, and salt myself (Taylor but not FAS-DPD). I checked in with the pool store for the alkalinity, calcium hardness, CYA, but only adjusted for CYA. I’ve learned the error of my ways.
The pool was closed 9/30/2023 and I opened 4/28/2024
Measurement at Opening (no closing measurement
)pH: 8+ (8.6 according to pool store…I know…)
Cl: 0
Current Measurement
FC: 5 (bringing it back up)
pH: 7.4
TA: 40
CH: 340
CYA: 50
My Guess
The pH was too high and calcium scale (of some form) began to appear.
What I’ve Done
- Read many resources here (scaling wiki, post after post after post …). Very informative, thank you!
- Kept the pH low for a few weeks, intending to continue for now.
- Brushed with a stainless steel brush everyday in one spot for a week: no noticeable change.
- Used pumice stone in a small area on bench: worked a bit, destroyed the pumice
- Used a metal paint scraper in a small area on bench: positive effect
- Used sand paper in a small area on bench: worked great!
Specific Questions:
- How do I gather the scale to test and identify it?
- The wiki/posts I’ve read say to scrape it off and pour acid on it, but it’s all under water and doesn’t just scrape off neatly. Am I missing something?
- Anyone willing to take a guess at the likelihood of success for keeping a low CSI of the course of the summer: 10% chance, 50%, 75%?
- I’m willing to live with this for the season and then take more aggressive measures (draining/sanding or acid washing) in the fall if low CSI has a realistic chance of success. But might take more aggressive measure now if I’m going to have to do it anyway.
- Is my CSI too low? How low can it be?
- I thought I saw a note about being careful not to damage your heater in this process, maybe because of low CSI? But I can’t find that again, should I be concerned about this?
More Context
I’m a pretty new/novice pool owner (1.5 seasons). I “maintained” the pool over this winter and opened myself for the first time. Unfortunately, by “maintenance” I mean I did nothing. If I’m honest, pool chemistry over the winter didn’t even cross my mind, it does now. I’ve been learning by reading online, followed by trial and what feels like a big error. I brushed heavily as instructed for the first summer and continued brushing at least weekly last year. As mentioned previously, I tested and balanced regularly (as best I knew at the time). Since finding TFP I’m using the FAS-DPD and testing almost daily and feel much more confident about the chemistry I’m maintaining.
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