Question about rough plaster and zero alkalinity acid treatment

[aquaN00b]

Hello everyone! It's your favorite pool n00b back to pester y'all again ;-)

My plaster looks really nice. There's no stains! But it is rough as heck. Like, scrape your knee rough if you hit the ledge under water or something. Anyway, I was reading this super helpful article and was thinking of doing the no drain acid treatment. Then I read that plaster pools usually last 20 years. This pool was built in the 70's and I *think* it's the original plaster. The previous owners kept good records of most things and I don't see anything about a re-plaster over the years.

Should I just skip the acid treatment and re-plaster since it's old? I can grab a pic of the plaster tomorrow if it's helpful.

Here's my numbers:
CSI: .12
CH: 350
CYA: 50
pH: 7.7 (I use mostly liquid chlorine)
TA: 80
Temp: 84F

 

[onBalance]

Try to determine whether the roughness is due to calcium scaling (on top of the plaster surface), or from a very etched surface. or from very poor troweling workmanhip.
If it is scaled, then an acid treatment may be able to remove the scale.
If it is etched or from original bad troweling, then draining the pool and sanding or polishing the rough areas can be made smooth. A re-plaster is another, but more expensive option.

 

[aquaN00b]

Well I'm really out of my depth here (Ha!), But after looking at some stuff on YouTube, I think it's just time for a resurface. If I had to pick anything maybe it's etched? I say that because of I look really close i can see Pebble/agregate. But it could be that's how it's supposed to be? Not sure. I looked at etching videos on YouTube and Mines not blotchy like the videos were, it's all very uniform. I'm including a picture maybe a trained eye could see. Also in this guys video, his surface looks a bit like mine and isn't really smooth plaster, it's got a roughness to it. I'm going to dig around for any paperwork on a resurface and also have another look at my pool inspection to see if anything was noted 3 years ago when I bought the house

 

[onBalance]

That plaster job is not fifty years old. It appears to be a relatively modern pebble finish. If it is pebble, and not quartz, then it is naturally a rough or bumpy surface. If so, there is nothing wrong about your plaster finish.

 

[aquaN00b]

That plaster job is not fifty years old. It appears to be a relatively modern pebble finish. If it is pebble, and not quartz, then it is naturally a rough or bumpy surface. If so, there is nothing wrong about your plaster finish.

Gotcha, ok. Like I said, out of my depth. My only experience with concrete pools are a very smooth plaster surface, so the roughness of it had me wondering. I don't think it's a true pebble surface as you can only see pebbles/aggregate if you look really really close. I think it must be a finish like that guy in the video. I found my pool inspection and it looks like it's fine (below). So I should be good with a CSI of .12 then? Should I try to keep my Ph lower than 7.7? It pretty much stays there all summer without me having to do much. Thanks for the help!

 

[onBalance]

Okay, it sounds like your plaster finish is a quartz finish. Most Quartz finishes are made to be smooth. Since your surface is rough, I suspect that it has been etched. Either from a prior acid wash or bath, or from long-term poor (aggressive) water balancing (low CSI). An etched surface is often consistent in appearance and color.
Your current water balance is perfectly fine. Allow the pH to stay at 7.7 or even slightly higher.
As I previously mentioned, it is possible to drain and sand that quartz surface to make it more smooth.

 

[aquaN00b]

Okay, it sounds like your plaster finish is a quartz finish. Most Quartz finishes are made to be smooth. Since your surface is rough, I suspect that it has been etched. Either from a prior acid wash or bath, or from long-term poor (aggressive) water balancing (low CSI). An etched surface is often consistent in appearance and color.
Your current water balance is perfectly fine. Allow the pH to stay at 7.7 or even slightly higher.
As I previously mentioned, it is possible to drain and sand that quartz surface to make it more smooth.

Ok cool, thanks! Yeah I'm not sure how the previous owners were at maintaining the pool, but I know they weren't using a good kit like the one TFP pools recommends. I know they used Trichlor pucks sooooo lol. Either way, as long as the finish is in good shape and I'm keeping balance, it should be good for a while until I need to do something. Thanks again for all the help!