Large dark areas on liner floor of pool

[richmgreen]

All though I am not new to pool care, I wasn't sure where to post this issue. In the center of the picture (attached), you'll see the stains on the pool floor. I tried brushing, vacuuming and rubbing them out. Won't go away. My pool readings are in good shape.

FC 6.0
CC 0
TC 6
PH 7.5
TA 110

Any idea what it can be and how to get rid of it?

Thanks,
Rich

 

[woodyp]

Is this a liner pool or plaster?

 

[Texas Splash]

Rich, would you mind also showing your CYA reading please?

 

[richmgreen]

CYA is 55 and the pool is a liner

Thx

- - - Updated - - -

CYA was running low at about 40. Just boosted to 55. I'd like to get it even a little higher. Started noticing the areas last summer. CYA almost 0 when I open pool each spring.

 

[richmgreen]

Liner

 

[Texas Splash]

Depending upon the type of stain it is, you might like to try a Magic Eraser or try placing a vitamin C tablet on the stain and see if that does anything. Some folks will also try crushing the cheap vitamin C tabs (ascorbic acid) in a sock and setting it on the stain for a few minutes. Maybe one of those will work for you? Let us know how it turns-out.

 

[richmgreen]

It's some fairly large areas, so I will try the magic eraser first. Any ideas on what causes these types of stains? Something I need to do differently or change ?

 

[richmgreen]

Is it possible to be coming from underneath the liner ?

 

[richmgreen]

The magic cleaner didn't remove the stain. It did however make it less "slippery" ... if that means anything