Organic vs. Metal Stain (Help Needed)

[axfx]

After opening the pool, organic debris had fallen into the pool (our cover was not on correctly), and I believe organic compound had spread. It was in there for approximately 6 months. However, after shocking the pool and taking the FC up to 35 for about a day (I have a CYA of 90), I saw little to no improvement.

I am going to do a Vitamin C test tomorrow but I do not believe it is a metal stain. It is the first time it has happened this us and we test the well water every year. Please tell me if it looks different to you.

If it is a long-running stain from organic matter for ~6 months, is there a way to remove it with chlorine or am I going to have to repaint / do an acid wash of the pool?

 

[axfx]

Another data point, the deep part of the pool seems to be completely unaffected by the staining. I don't know what to do, would appreciate any advice!

 

[zea3]

If you had a bunch of leaves and organic debris sitting there for a while it may be tannin stains. Try placing a chlorine tablet directly on the stain for about 30 minutes and see if it lightens it after you finish the vitamin C test. Tannin stains will lift after a few days exposure to higher chlorine levels. I have a few questions about the stain. Does it feel rougher than unstained areas? What type of chlorine do you normally use? Could you post a complete set of test results?

 

[axfx]

If you had a bunch of leaves and organic debris sitting there for a while it may be tannin stains. Try placing a chlorine tablet directly on the stain for about 30 minutes and see if it lightens it after you finish the vitamin C test. Tannin stains will lift after a few days exposure to higher chlorine levels. I have a few questions about the stain. Does it feel rougher than unstained areas? What type of chlorine do you normally use? Could you post a complete set of test results?

It 100% went away with the Vitamin C test. I took a sample of my pool water and also a sample of the well water to the pool store (until my TF-100 arrives). The pool water has .4 PPM copper. The well water does not.

No idea how that happened...I have no heating elements in my pool. The PH was at 6.8 (which is the minimum it tests for) and the alkalinity was at 33. I am addressing those now. Still no idea what the acidic water was wearing at...

 

[zea3]

Some dry chlorine products, especially if they have blue in the name, contain copper. Some algaecides also contain copper. If you have used any of these products the copper will build up until it starts to drop out of solution and leave stains.
However, vitamin C doesn't remove copper stains. Vitamin C will turn copper stains black. Iron is removed by vitamin C. Since the iron has deposited on the pool surface you may not have measurable iron in the water. Did they test for iron at all? As you bring up your pH and chlorine you may see the water turn a rusty, muddy brown color. What you can do when that happens is use pillow stuffing in the skimmer to filter out the oxidized iron. Pillow stuffing can be rinsed and reused until the pool is clear. People also make iron filters that work well to clear oxidized iron out of the pool.