Just what IS that black film clinging to the inside of my skimmer?

[subedoo]

It is around the water line in the thru-wall skimmer and wipes off with a terry towel but comes back within days. I used a scum ball in the skimmer which got completely black. I was not able to clean the scum ball at all using Dawn liquid dish soap. The black scum is still on it. Not sure if it's doing any good now or not so I'm leaving it out of the skimmer. I don't have a lot of bathers in the pool. Sadly, the pool is used by 2 or 3 people for only 12 to 15 hours in a week with good weather. My numbers are always good and I have crystal clear water. There is no evidence of this black film anywhere else -- not on the ladder and not on the vinyl pool walls.

Is it body oil? If it is, I can't imagine what it must be like in a pool with a lot of bathers.

[aylad]

Body oil, suntan lotion, sunscreen, plus the other dirt that gets introduced to the pool. I have to clean my entire waterline once a year or so with baking soda paste and a scrub sponge. My bather load is primarily kids, so there's a lot of sunscreen introduced. You could limit the sunscreen, but personally I'd rather just clean the waterline once a year.

Janet

[daisy11]

It could be "pool goo," especially if your liner is new. I had a black film appear on the inside of our skimmer shortly after our pool was installed. I went to the pool store where we purchased the pool, and they told me it was "pool goo." I laughed and asked them if that was a technical term...and they unsmilingly said yes and even gave me a printout describing it, which I tucked in my pool folder! Here's what it says: "New vinyl liners often have a buildup of sticky substance that adheres to the bottoms of feet and sometimes turns black. This is plasticizer migrating from within the liner, and is usually only prevalent in colder water temperatures with new vinyl liners. Brushing and shocking can help reduce this buildup, as can increasing the water temperature. This buildup usually goes away on its own as the liner ages and the water temperature warms up."

If that's what it is, just wipe the side of the skimmer periodically, and eventually it will stop appearing.

[fcfrey]

I don't know if you are using BBB or pucks but here is a testimonial ---- Prior to going BBB we had the black oily deposit inside the skimmer and also on the steps. The better half scrubbed the waterline weekly and did the skimmers and steps every day. The pool stores said it was pollution and lotion etc. and then proceeded to sell us stuff to clean the gunk off.

We switched to BBB last year after 4 years of the pool store nonsense. We lost the bathtub ring almost immediately. This spring I used 12 pucks to raise the CYA a bit and guess what, ------ the black gunk came back within a few days.

The CYA is now up where I want it, the pucks are gone and we're back to bleach ONLY. NO MORE BLACK GREASY GUNK!!!

Anybody want a half bucket of pucks cheap, send me a PM.

[SLS]

I keep a puck in my skimmer at all times and use bleach to "adjust" the level. I always have the black goo in my skimmer which I too believe is the puck. I haven't noticed it anywhere else.

[subedoo]

I don't know if you are using BBB or pucks but here is a testimonial . . .

I have used BBB since the pool was installed late last season. My pool has not seen a puck. I keep my chlorine on the "high side" of the recommended level (at 6 or 7) with my CYA at 35~40.