Yellowing on new plaster

[penquinizer]

Hi!

We got our pool replastered with 50% quartz about a month and a half ago. I noticed that there are some yellowing and what seems to be yellowing / uneven-ness of the quartz density in some areas.

Some of the yellowing, pictured below, I think may be light algae growth but it's not completely scrubbing off to match in color. You can kind of see it on the middle step edge in comparison to the middle.


The other problem can be seen here. This doesn't seem to be algae. The surface here is smoother in texture than the rest of step. You can see it from the wall to middle of the phone.

 

[ajw22]

Does your pool pass a Overnight Chlorine Loss Test?

 

[JoyfulNoise]

Your image links are not working. You either have to upload the images to TFP or simply copy and paste the images into the post. Using links from third party image storage systems doesn't work well

 

[ajw22]

Your image links are not working. You either have to upload the images to TFP or simply copy and paste the images into the post. Using links from third party image storage systems doesn't work well

I was able to view the images within the post earlier today.

May be a bug with the new server. @Leebo

 

[penquinizer]

Updated the images!

The plastering people finally got back to me and said they think it is calcium build up which is why the one by the get is 'cleaner' and 'rougher' than the rest of the pool. Recommended me dropping ph below 7.2 for a few days and scrub with a metal wire brush.

 

[Bperry]

Updated the images!

The plastering people finally got back to me and said they think it is calcium build up which is why the one by the get is 'cleaner' and 'rougher' than the rest of the pool. Recommended me dropping ph below 7.2 for a few days and scrub with a metal wire brush.

I would test your water first before doing that.

 

[penquinizer]

Yeah. I will test my water again tomorrow. Last I checked my ph was on the higher side and calcium hardness around 450.

 

[penquinizer]

Been working to keep my ph around 7.2 while calcium hardness is in the 450 range.

I wonder if that clear patch area is due to the return jet blowing over that specific area and washing away some of the mix during the first few days.

 

[Bperry]

Been working to keep my ph around 7.2 while calcium hardness is in the 450 range.

I wonder if that clear patch area is due to the return jet blowing over that specific area and washing away some of the mix during the first few days.

Not likely. Having noticeable calcium buildup in one month also seems unlikely. Was it different a month ago?

 

[penquinizer]

Got it. Yeah, I don't remember it looking like that when they originally finished. Disappointingly enough, I did not take a photo from that side. I do have one of the opposite side of the steps.

Would that staining occur if chlorine levels weren't high enough during the first few weeks and there was a bit of algae growth? The pool was officially filled on Feb 9th. Maybe I can try shocking the pool to see if its algae residual? That doesn't seem to answer the textural difference in that area though. (green highlight area feeling a little rougher)

Potentially a result of bad plastering? The pool company is saying calcium buildup due to high ph and recommends dropping ph to around 7.2 for a couple of days and then scrubbing the 'red highlighted area' / rest of the pool with a wire brush. Then if the 'green' area feels too rough compared to the rest of the pool, use sandpaper to sand it down a bit.

That seems like there's a potential to brush off too much and doesn't answer what's causing the textural difference to me.

Photo of area main area with the biggest visual difference.


Photo of the opposite side of steps during the filling. Ill try to capture some photos on that side later today.

 

[Bperry]

Got it. Yeah, I don't remember it looking like that when they originally finished. Disappointingly enough, I did not take a photo from that side. I do have one of the opposite side of the steps.

Would that staining occur if chlorine levels weren't high enough during the first few weeks and there was a bit of algae growth? The pool was officially filled on Feb 9th. Maybe I can try shocking the pool to see if its algae residual? That doesn't seem to answer the textural difference in that area though. (green highlight area feeling a little rougher)

Potentially a result of bad plastering? The pool company is saying calcium buildup due to high ph and recommends dropping ph to around 7.2 for a couple of days and then scrubbing the 'red highlighted area' / rest of the pool with a wire brush. Then if the 'green' area feels too rough compared to the rest of the pool, use sandpaper to sand it down a bit.

That seems like there's a potential to brush off too much and doesn't answer what's causing the textural difference to me.

Photo of area main area with the biggest visual difference.
View attachment 562162

Photo of the opposite side of steps during the filling. Ill try to capture some photos on that side later today.
View attachment 562161

Without accurate water tests you’re flying blind. Dont fly blind, it hurts when you run into something unexpected.

 

[penquinizer]

Without accurate water tests you’re flying blind. Dont fly blind, it hurts when you run into something unexpected.

Right.

My test today is around the same numbers as before.

FC - 1.5 (added more today)
pH - 7.2 (been maintaining this almost daily)
TA - 40
CH - 450-475
CYA - 25 (Was around 45 last week. Unsure why it's dropping so quickly)

 

[Bperry]

Right.

My test today is around the same numbers as before.

FC - 1.5 (added more today)
pH - 7.2 (been maintaining this almost daily)
TA - 40
CH - 450-475
CYA - 25 (Was around 45 last week. Unsure why it's dropping so quickly)

Youre way low on FC. Might be worth a try getting it back into normal levels for a while and see ifnit improves.

 

[penquinizer]

Adding some today!

Should i raise TA levels to the 70 range or will that cause my pH to rise faster?

 

[Bperry]

Adding some today!

Should i raise TA levels to the 70 range or will that cause my pH to rise faster?

If the test came from a taylor kit then you should get it up to 50ppm. If the test came from a pool store or test strip,you can ignore it until you test with a taylor kit.

 

[penquinizer]

Yup! From a Taylor kit. I got it up to 50ppm yesterday.

Currently battling with pH spiking way too fast. Checked this morning around 10am and it was well below the 7.0 yellow on the test kit. Didn't add anything but tested it 4 hours later and it has spiked to darker than 8.0

This didn't use to happen before replastering with the pH being more consistent even with the fountain having a bigger splash.

 

[ajw22]

Currently battling with pH spiking way too fast. Checked this morning around 10am and it was well below the 7.0 yellow on the test kit. Didn't add anything but tested it 4 hours later and it has spiked to darker than 8.0

This didn't use to happen before replastering with the pH being more consistent even with the fountain having a bigger splash.

That is normal for a year or more after new plaster as it cures.

 

[penquinizer]

Thanks for the insight ajw22!

These are the numbers Ive been aiming for
FC - 3.5
CYA - 40
pH - 7.2 - 7.4
TA - 50

While I haven't done what the pool builders asked of scrubbing the pool with wire brush, I've been working to scrub off the yellow. This has been working pretty well.

The weird transition on the step is still there so unsure what next steps would be. Interestingly enough, I found an image of the steps from the last day of pool start up. It seemed to already exhibit the same transition already. But my eyes could be playing tricks on me.

My photo from a few weeks back


Photo from start-up handoff day (7 days after filling)

 

[onBalance]

I am thinking that the yellow areas are from some calcium build up due to the plaster "dust" hardening in those areas that didn't get brushed during the first two weeks. If so, that calcium deposit can be easily removed by sanding with 80 grit wet&dry sandpaper. It does NOT harm the plaster and will actually make the sanded areas smoother than the other non-yellow areas. A wire brush is not as effective as using sandpaper.
Just an observation.

 

[ajw22]

You can buy hand plaster polishing pads at...

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