- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
Hi, I'm hoping the TFP plaster experts can help keep me on the straight and narrow.
I’m concerned this plaster is failing and wondering the best things to do to make it last and also look good. I took over this 7300 gal pool 5 months ago, just helping out family. First test was:
FC 2.5
CYA 0
SWC running 6 hrs per day at 100%; now 4 hours after adding 40 ppm CYA and keeping FC around 2-4
pH 8+ (2 demand drops to get to 8)
TA 130
CH 200 (added 50)
Here’s a picture of the scale. I collected some and there was instant healthy fizz with MA.
So my plan was/is run the pool around -0.6 CSI and see if the scale will dissolve. After several months with -0.6 CSI just after acid addition pH 7.4, then back to 0.0 in a few days before the next acid addition at pH 7.9/8.0 (there’s a lot of aeration). Maybe there’s less scale, maybe not. Should have used Kim’s suggestion and taken before/after pics, but bottom line is that it’s still a blemish.
Today’s numbers:
FC 4
CYA 40
pH 7.9 (1 drop acid demand 7.6, 2 drops 7.4, added 300 ml MA for target 7.5)
TA 60
CH 275
Temp 28C (82F) with hot days lately pushing water to 32C (90F)
A few weeks ago, I emptied the skimmer and found some bits of scale that had been vacuumed up, and I thought winner winner chicken dinner.
So I took a plastic scraper and did some duck diving and was making a bit of progress but not quick enough for me. And shock horror, I knocked off this chunk of plaster. Was a bit deflated by that.
On the underside, I hope you can notice the white streak extending from the end of my finger to about halfway along the chunk. I peeled some of that off and it fizzes just like the scale. I also tried some of the pool plaster, and it fizzed but not vigorously. Does this mean that scale has gotten under the plaster? Or filled a fissure or something?
Saved the chunk and I’m wondering if it can be epoxy’d back in.
I was swimming in the pool on the weekend and noticed I could dislodge the odd piece of scale with my toes. Since it is not going away quick enough and I have a couple months left of warm water, my plan was to buy a pumice stone and a weight belt and try to ease it off without scratching the glass beads too much. But now I’m a bit antsy about it.
Two weeks ago, I emptied the skimmer and saw the odd chunk of plaster. Uh oh, I didn’t like that. I emptied the skimmer yesterday and saved the chunks, picture below. You can see some scale and also beads and plaster. The pieces fall apart very easily.
I felt some of the scale with my fingers, and I’d say in many locations, there’s both scale and an erosion of plaster just below the scale, a groove in some places and dimples small and large in other spots, some deep enough that they’re through the glass bead layer and into pure plaster.
So what do the plaster experts think about this? See background below if needed.
Background:
The pool is about 5 years old. I know the plasterer and he told me that the owner, who’s also a friend of his and they socialise, didn’t do everything they were supposed to do (he visited often so he knew) and God knows about the water chemistry. The plasterer was new at doing pools at the time, but ran a business prior to that in cementitious products including paver manufacturing, and he’s a smart guy.
When I took over I talked to the owners about the scale and they said they’ve struggled with that stuff. At one point they said ‘yeh, had to scrape it off with a screwdriver’ That comment made me shiver, but I think the screwdriver was used on the stone under the water blade a few years ago. At another point they asked what to use and I suggested pumice stone but stay away from the waterline and marker tiles cause anything glass will scratch, including the glass beads in the plaster. (more info from TFP, thanks!)
They’re very busy people and needed to go with a service to keep up with kids and careers. I know the brushing didn’t get done after pool fill, but that’s all I know first-hand. I think they did the pool store routine for a year or so, then a series of pool services, the last of which left the pool way over pH 8 and 1.0 CSI. It’s not out of the ordinary for a cheap pool service here to just run the SWC hard, no CYA, cup or two of acid once a weekish, quick skim and run to the next one ($50 a week plus chemicals but including acid); stretches to $50 a month in winter.
Solar heating was added last year, the pool is square and level, pretty, with massive aeration from venturis on the returns, plus a stone feature wall with water blade. It gets a lot of use daily when the sun is shining, anything from 2 to 6 hours.
I have the same finish by the same plasterer in my own pool, and it’s not often I see glass beads and I’ve never seen plaster in the skimmer.
Help :?
I’m concerned this plaster is failing and wondering the best things to do to make it last and also look good. I took over this 7300 gal pool 5 months ago, just helping out family. First test was:
FC 2.5
CYA 0
SWC running 6 hrs per day at 100%; now 4 hours after adding 40 ppm CYA and keeping FC around 2-4
pH 8+ (2 demand drops to get to 8)
TA 130
CH 200 (added 50)
Here’s a picture of the scale. I collected some and there was instant healthy fizz with MA.
So my plan was/is run the pool around -0.6 CSI and see if the scale will dissolve. After several months with -0.6 CSI just after acid addition pH 7.4, then back to 0.0 in a few days before the next acid addition at pH 7.9/8.0 (there’s a lot of aeration). Maybe there’s less scale, maybe not. Should have used Kim’s suggestion and taken before/after pics, but bottom line is that it’s still a blemish.
Today’s numbers:
FC 4
CYA 40
pH 7.9 (1 drop acid demand 7.6, 2 drops 7.4, added 300 ml MA for target 7.5)
TA 60
CH 275
Temp 28C (82F) with hot days lately pushing water to 32C (90F)
A few weeks ago, I emptied the skimmer and found some bits of scale that had been vacuumed up, and I thought winner winner chicken dinner.
So I took a plastic scraper and did some duck diving and was making a bit of progress but not quick enough for me. And shock horror, I knocked off this chunk of plaster. Was a bit deflated by that.
On the underside, I hope you can notice the white streak extending from the end of my finger to about halfway along the chunk. I peeled some of that off and it fizzes just like the scale. I also tried some of the pool plaster, and it fizzed but not vigorously. Does this mean that scale has gotten under the plaster? Or filled a fissure or something?
Saved the chunk and I’m wondering if it can be epoxy’d back in.
I was swimming in the pool on the weekend and noticed I could dislodge the odd piece of scale with my toes. Since it is not going away quick enough and I have a couple months left of warm water, my plan was to buy a pumice stone and a weight belt and try to ease it off without scratching the glass beads too much. But now I’m a bit antsy about it.
Two weeks ago, I emptied the skimmer and saw the odd chunk of plaster. Uh oh, I didn’t like that. I emptied the skimmer yesterday and saved the chunks, picture below. You can see some scale and also beads and plaster. The pieces fall apart very easily.
I felt some of the scale with my fingers, and I’d say in many locations, there’s both scale and an erosion of plaster just below the scale, a groove in some places and dimples small and large in other spots, some deep enough that they’re through the glass bead layer and into pure plaster.
So what do the plaster experts think about this? See background below if needed.
Background:
The pool is about 5 years old. I know the plasterer and he told me that the owner, who’s also a friend of his and they socialise, didn’t do everything they were supposed to do (he visited often so he knew) and God knows about the water chemistry. The plasterer was new at doing pools at the time, but ran a business prior to that in cementitious products including paver manufacturing, and he’s a smart guy.
When I took over I talked to the owners about the scale and they said they’ve struggled with that stuff. At one point they said ‘yeh, had to scrape it off with a screwdriver’ That comment made me shiver, but I think the screwdriver was used on the stone under the water blade a few years ago. At another point they asked what to use and I suggested pumice stone but stay away from the waterline and marker tiles cause anything glass will scratch, including the glass beads in the plaster. (more info from TFP, thanks!)
They’re very busy people and needed to go with a service to keep up with kids and careers. I know the brushing didn’t get done after pool fill, but that’s all I know first-hand. I think they did the pool store routine for a year or so, then a series of pool services, the last of which left the pool way over pH 8 and 1.0 CSI. It’s not out of the ordinary for a cheap pool service here to just run the SWC hard, no CYA, cup or two of acid once a weekish, quick skim and run to the next one ($50 a week plus chemicals but including acid); stretches to $50 a month in winter.
Solar heating was added last year, the pool is square and level, pretty, with massive aeration from venturis on the returns, plus a stone feature wall with water blade. It gets a lot of use daily when the sun is shining, anything from 2 to 6 hours.
I have the same finish by the same plasterer in my own pool, and it’s not often I see glass beads and I’ve never seen plaster in the skimmer.
Help :?
