Small rust spot vitamin c

[Sbgamecock]

Hi. I have swg gunite pool that is just over 1 year old. Filled with city water and no metal (that I know of). Had a small pea size rust stain in my hot tub that I rubbed on it and went away a couple weeks ago. It came back and I put 3-4 vitamins in a sock and crushed them and let it sit on the spot for about 40 minutes. when I came back to a large brown stain about the size of a fist was where the sock was. I can’t clean it with a brush, or rubber ”stain eraser” Does this sound like copper or something else? No copper pipes, no exposed metal near my pool.

I started a slam yesterday as I have been losing fc was dropping more than normal. But really clear water so really just making sure with the slam and then was going to raise the cya which is low and probably the cause of the chlorine depletion. My oclt was between 1-1.5.

fc:13
cya: 30
ph: 7.2

any help is appreciated

 

[YippeeSkippy]

Hiya Sbgamecock..... just a couple of months till football, eh? Welcome to TFP.

The first bit of stain could have been some fertilizer accidentally strewn into the pool or something else? But I'm concerned that you left the sock filled with Vitamin C tablets on it for so long? We normally suggest just 2-3 minutes.

I'm going to invite some smarter than me people in her may be able to figure out what to do. @JoyfulNoise @onBalance

Maddie

 

[onBalance]

That stain is not from copper. Not sure what it is either. It may be something that got mixed in with the plaster finish.
That stain is not affecting the water balance in any way, so don't worry about that.
Purchase a sheet of 80-grit wet&dry sandpaper and hand sand that area for a minute. I hope that will remove the discoloration.

 

[JamesW]

You can try some sulfamic acid directly on the spot.

Jack's #2 is sulfamic acid, but it's way more than you would need.

STAIN SOLUTION #2 – The Copper & Scale Stuff | Jacks Magic

jacksmagic.com

 

[Sbgamecock]

Thanks everyone. Update, it bleached out overnight and is much smaller and not nearly as dark so hopefully it will take care of itself. On the bright side, I finished my first SLAM that I may not really have needed anyway Adding more CYA today. This site is great and thanks to everyone . And. Maddie, yep, I’m counting down to football season.