Copper staining -- need advice on removal


TFP Expert
Mar 2, 2011
Based on the wrinkles, high cyanuric acid and report of low pH and TA, I suspect that the overuse of tabs kept the pH low enough to keep the iron from staining.

Raising the pH caused the iron to precipitate out.
Interesting observations, thanks James. We have had wrinkles in the liner for the past three years but they have gotten worse over time. Thankfully we don’t have anything torn or popped out from the top, but I have been keeping a close eye on things. I’m not ready to replace a liner yet, but considering resetting it.

Interesting note about the low PH, TA and high CYA in combination with the chlorine and tabs ended up causing me a huge mess. And I think I I’ve read that tabs have stabilizer in them, right? It looks like I really overdid it, probably mostly on the chlorine front. I’ve laid off on adding anything further at this time. I’m gonna ride out the next few days to lower my FC naturally and then try the ascorbic acid. It looks like it will be more effective with lower FC from what I am reading.

I am considering a half drain and refill — would that be worth it?

Man, and here I was trying to do the right thing!

THANK YOU all for your advice and helpful links. I have a little more reading to do, but I take comfort in having a little more knowledge about what’s causing this.


Active member
May 14, 2017
I had black staining on my pebble Finish pool because a service man put the wrong chemical in. I had tried all the methods above (vitamin C Jacks Magic etc.) but nothing worked. I finally had to have someone come in, drain the pool and acid wash it. That worked.
One final update: We applied the ascorbic acid over the weekend with success! There’s still one patch where there is a stain but I will spot treat that. Overall it looks much better! I added a sequestering agent after the AA and will give it a good backwash today. Will be monitoring my levels for PH and chlorine in the coming days to gradually bring them back to normal. Thanks everyone for the advice. Looks like this was an iron stain indeed.


  • Like
Reactions: JamesW