Black scum ring in skimmer

[Mid-West Infidel]

First of all a brief history-

We've had the pool for about 8 years now. Seems like every year I have some kind of algae issue. I think part of my problem is all the trees around me... I only get full sun from about 10am to 3:30 pm. I found TFP late last year and after some thought, decided to try the liquid chlorine method this year. Actually, want to use up my remaining 3 in 1 tabs, while monitoring CYA. I figure when it starts creeping up, I'll make the switch.
I just installed a new liner, filled pool and water is nearly balanced (see below). Like last year, I am already starting to see a black scum ring developing in the skimmer box. No one has been in the water yet, so I don't think lotions, etc. are a concern.
I installed new sand in my filter last year, by the way.
Can anyone tell me why this is happening and how to correct it?
TA-60
CH-110
pH-7.4
CYA-<30
FC-12.5 We've had a bit of rain so I did add some liquid bleach (obviously too much)...
CC-0.5
BD-1

You can start to see it in this pic:

View attachment 38400

 

[kimkats]

I have the same thing. I just scrub it with a Magic Eraser and it is good for a while. I do not know what it is but I too have trees around.

Kim

 

[Scuba_Steve]

Here you go. It is also characterized by a ring in the skimmer as you described.

http://www.cgtpoolliners.com/tb-7

 

[Mid-West Infidel]

Here you go. It is also characterized by a ring in the skimmer as you described.

http://www.cgtpoolliners.com/tb-7

Thanks for the link Scuba_Steve. The stuff ends up like tar, that's for sure!

 

[Casey]

You can buy a scum ball n throw it in the skimmer box. It'll absorb that and keep it from adhering to the skimmer.

 

[Mid-West Infidel]

You can buy a scum ball n throw it in the skimmer box. It'll absorb that and keep it from adhering to the skimmer.

Never heard of the scum ball, but I Googled.... Sounds like a plan.
Thanks!!!