Can't get rid of waterline ring

[Tym2Fish]

Hi All,
Fiberglass pool I installed in January. In April, it was screened in. I've got the TF-Pro test kit and water is right on. Just FYI, it's salt.

Now that South Florida is in the rainy season, I've noticed a ring around the waterline of my pool. It's not easy to get off. After lots of scrubbing I tried my fiberglass cleaner for my boat and it works well to remove it. The problem is, every time it rains the ring comes back. It's very prominent where the returns are hitting the side of the pool and the ring goes around about 8 feet or so from where the returns hit the side of the pool so it's coming from the pump apparently, though I doubt it originates there.

I installed a new filter and it's did the same thing the next day. The skimmer is clean and even when we go a week or two without getting in the pool, it still comes back after it rains. Any thoughts would be appreciated.

 

[Rancho Cost-a-Lotta]

Do you have any photos of the stain? What color is it? I'm having a hard time picturing it.

 

[Tym2Fish]

It's sort of a dark grey. Here's a pic.

 

[Tym2Fish]

FYI I dropped the water level this morning so that's why it's so high. Rained a lot last night.

 

[mknauss]

Is it tacky/sticky at all? As it occurs after rains, something on the screen - pollutants, etc?

 

[Tym2Fish]

That was my first thought but I can't figure out a way to be sure. With the screen being a few months old I could only think it would be something in the manufacturing if that was the actual issue.

Not sticky at all. Won't rub off with sponge and water. Almost like trying to get off old dry erase marker.

 

[mknauss]

I get something like that in my skimmer. I use dilute Simple Green and a scrub sponge.

I suspect it is something from the screen.

 

[Tym2Fish]

It would be a likely culprit. Now the question is what to do about it. Scrubbing a waterline three or four times a week is getting quite old.

 

[mknauss]

Try a scum sponge in the skimmer. See if you can catch it there.

 

[ajw22]

Try some scum sponges in the pool.

 

[Tym2Fish]

Never heard of a scum sponge. Will research now.

 

[Newdude]

I keep 2 tennis balls in each skimmer at all times. They work wonders sucking up oils/sunscreen/etc.

 

[Tym2Fish]

I've got tennis balls on hand. I'll put them in now.

 

[ajw22]

Never heard of a scum sponge. Will research now.

Amazon.com

Cheap Oil-Absorbing Scum Sponge - doing the job or not?

Are the cheap Oil-Absorbing Scum Sponge (such as Scumbug) any good for Spa / Hot Tub? After reading the reviews of the products in Amazon the buyers are divided between great product and worst product possible. Since I trust this forum, I ask for guidance. I have tried both and I can see and...

www.troublefreepool.com