Grey stains on my liner

[jake0110]

I noticed some grey stains on my vinyl liner after removing the solar cover. We have had a lot of rain and cool weather in the Northeast, so I haven't been in the pool much this year. The cover was on for a few weeks, and I didn't check much underneath it.

When I finally pulled the cover off, there was some algae (not much), and these grey stains. Chlorine level was 0, and pH was 6.8. I raised both to normal, and cleaned the pool. Everything looks great, but there are still stains on the liner. I can't scrub them off with a brush or my hands.

Any ideas?

 

[X-PertPool]

Leave a tri-chlor tab on the area for 10 min remove the tab and if it lightened it's organic
Try Vitamin C or Pool Stain treat spotting bag etc. for 10 min; remove and if it lightened it's in-organic
Although a gray stain does scare me a little, it does sound like the "vinyl plague" which comes from underneath the liner and permeates it's way through. This makes it very difficult to treat, you have to realize that vinyl isn't a complete barrier for everything; for example a magic marker mark on the backside of vinyl with eventually permeate it's way through.

 

[frustratedpoolmom]

Don't put a puck on vinyl, you'll permanently bleach it.

Those sound like organic stains that should fade in a couple of months provided you maintain proper FC levels according to the CYA chart.

I used to have them in my pool before I found TFP and I no longer have them because I keep my FC stable.

I was basically told it was black algae (it wasn't) then I was told it was something under the liner showing thru, like a mold or fungus.

Like I said, two months of BBB and the stains were gone and never returned.

 

[jake0110]

i'll probably stick with the steady as she goes method and see what happens. i prefer not to add anything if i can help it.

thanks!