concrete around pool lighter from being under winter cover - pics

firefox2017

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Mar 24, 2017
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Uniontown
Anyone ever experience this? The lighter portion around the pool was that under the winter cover. This was after the 2nd winter the pool has seen.

We are hoping to fix since it's rather unsightly. Tried 3000PSI pressure washer with very minor improvement. Cover has been off for over a week now

Thanks - Eric

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bmoreswim

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Jul 16, 2012
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Is the concrete stained? Or did the mix have colorant in it? I’m wondering if the colorant or stain didn’t like being frequently saturated during the off-season and it was neutralized for lack of a better word. The lighter areas look to be where the straps were based on the repetitive pattern and those would have been wet most consistently due to less air flow due to tighter contact. None of which helps you but just trying to ID at this point.
 

ajw22

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Jul 21, 2013
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Dirt, acid rain, whatever you want to call it that falls from the sky or runs off in your area. There is more pollution around then we realize. I see the same thing on my pavers where my pool cover is and where we have some outdoor rugs down.
 

bmoreswim

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Hmm. It could be related to the curing process. This can take place over several years. The concrete was likely saturated much more in the lighter areas. I don’t know the science behind that concept. But honestly I don’t think there is much you can do. It will likely fade some over time, so at least become less noticeable.

Another idea is that it is efflorescence. This is not as commonly seen on flat surfaces as on walls. But it relates to water that brings minerals to the surface. It may have been the the consistency wet surface kept those minerals transferring up and to the surface. Here is a page about efflorescence. How Efflorescence Works
 

bmoreswim

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Dirt, acid rain, whatever you want to call it that falls from the sky or runs off in your area. There is more pollution around then we realize. I see the same thing on my pavers where my pool cover is and where we have some outdoor rugs down.
I was thinking that but power washing didn’t remove the dirt. So I’m not sure if that is the issue. 3000 PSI should have done it for dirt, etc.
 

Kjp300

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Jul 18, 2018
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Canfield ohio
My pool is 2 years old and the deck looks exactly the same as yours. Much lighter where the winter cover is over the concrete. I also have a pool house with a bar, and the concrete that is under roof is much lighter than the concrete that is exposed to the weather. So it definitely has something to do with the weather. Had a friend bring his 4200 psi power washer over and it lightened my concrete a little, but it is still very noticeable. Last year it blended better as the summer wore on. Not sure what to do about it, but it doesn't bother me that much. I am more focused on keeping my water well balanced and crystal clear.