Ascorbic Acid question

[mitch08]

Hey guys,

I have a bunch of iron staining in my vinyl pool. Im going to follow the pool school advice on how to get rid of it and I already ordered the AA.

In the meantime, I grinded up a bunch of Vitamin C and stuck it into a sock and put it on the worst spots of staining. It worked immediately. The thing is, the area I originally put the sock over is very white. It looks faded out. I started dragging the sock around with a brush and the stains lifted right away and no issues to the liner in any other spots. Just the initial spot of the sock.

So my question is, can AA in concentrated doses instantly fade a vinyl liner, or is it more likely that the spot was already faded a bit and I just didnt notice it? Or perhaps even the stain isnt 100% removed and the whiteness is what is left over? (This seems the least likely but I guess its possible)...

Thanks a million.

 

[chem geek]

Ascorbic acid is acidic, though not as much as Trichlor tabs/pucks, so it's possible that leaving it in one place for two long could result in some fading as it would be very concentrated. An overall pool ascorbic acid treatment would not be a problem since you wouldn't have the pH get below 7.0, but a spot treatment could have the pH get a lot lower depending on circulation in that area. The spot test is something you normally do briefly and don't leave it for many hours. If you only left it for 10 minutes or so, then I doubt the fading was from the ascorbic acid.

 

[mitch08]

Thanks for such a quick reply. Honestly, it wasnt anywhere near 10 minutes.
I think it was probably under 2 minutes.

Perhaps that part of the liner was just "duller" and I never noticed...

The iron stain itself wouldnt mess up the liner, would it?

 

[chem geek]

It could have a stain, but the ascorbic acid should have removed it. Not sure if it would leave a mark -- probably not, but I don't know enough about staining on vinyl.

 

[bk406]

That brief time of the ascorbic acid on the vinyl would not have faded it. My guess is what you are seeing is actually the result of clean vinyl. Over time, the iron will stain the vinyl but it will be much more subtle than on white plaster. In some cases, you may not even notice until it becomes fairly stained. The ascobic acid treatment just cleaned up an area and to your eye it looks faded relative to the vinyl around it. This is my best guess.
Have any pictures we could see?

 

[mitch08]

Thanks. I will take some pics as soon as I can. It might take me a few days since in NY now it gets dark at around 5pm and Im getting home later than that. But Ill definitely post some pics asap.

I think you are definitely onto something with seeing "clean vinyl" as compared to the area around it. But it just seems so much whiter and less blue in that area.
Its really strange.

Thanks again for your help as well as everyone elses!!!