Stain on vinyl liner

[Sierra54]

I just finished slamming our pool and have yellowish-green stain st the bottom of our pool. The stain was there last year so I wasn't suprised to see it as the water cleared. It does seem more pronounced after adding a starting dose of algimycin 600. I thought this was safe for liners so I'm not sure what may be causing this. What stain identification kit and process do you recommend to fix this?

Thank you.

 

[Texas Splash]

Might be a result of something under the liner. Have you trued the standard testing methods?
- Slide a chlorine tab on it to see if it's organic (don't let the tab just sit)
- Rub a Vitamin C tablet on it to see if it's iron
- Rub some dry acid on it in a thin sock to see if it's copper?

 

[Sierra54]

Might be a result of something under the liner. Have you trued the standard testing methods?
- Slide a chlorine tab on it to see if it's organic (don't let the tab just sit)
- Rub a Vitamin C tablet on it to see if it's iron
- Rub some dry acid on it in a thin sock to see if it'

I waited for the Jacks Magic ID kit to arrive and tried it last weekend. I didnt see any significant provement in the stains. There may have been a mild improvement after doing step #5. This involved applying stain solution #3, the O2 safe shock, followed by stain solution #2, copper &scale stuff.

Not sure if I should follow this path or should I have seen a more dramatic response? The pool was balanced as instructed per Jacks Magic.

Thank you.

 

[Texas Splash]

Were your instructions the same as the one listed HERE? If so, that points towards copper.