What is black substance?

[joseywales]

My FC seems to hold over night, this keeps appearing in my skimmer. It forms a ring of black "dots". I tried smearing it on an envelope Any idea what it is?

 

[mknauss]

I tried smearing it on an envelope

What did that show?

 

[joseywales]

Was trying to load it. It doesn't appear green to me Thanks

 

[mknauss]

Sticky, greasy, ???

 

[JamesW]

Likely to be lotion, body oils, hair products etc.

Are you getting a lot of swimmers?

Are people lathering up with suntan lotion?

 

[joseywales]

Hmm. I'll check it, but it didn't feel sticky. It smeared more like motor grease. Not a lot of swimmers, but two daughters, so.... I think we're on the right trail here.

 

[JamesW]

People lather up to lay in the sun and then they jump in the pool to cool off and then they have to reapply the lotion and so on.

At the end of the day, there is about a half of a bottle of lotion in the water.

 

[joseywales]

Unintentional test: we went away for the weekend, so I vacuumed the pool, brought Chlorine up to 6, covered the pool with our black winter cover, and later turned off the filter before we left.

It's been really hot! The only item I left in the pool was one large tube, to keep the cover tight. Came back today, all is well. No black gook at all. Pool bottom was clean. Chlorine was around 1. Doesn't prove anything, but makes me feel good. I'll keep testing FC overnight, but before we left it was holding. I really think it's lotion of some sort.

 

[zea3]

Some people keep a tennis ball in the skimmer to soak up oils and lotions, or you can get a scumball that does the same thing. You just have to swap them out periodically.

 

[joseywales]

Some people keep a tennis ball in the skimmer to soak up oils and lotions, or you can get a scumball that does the same thing. You just have to swap them out periodically.

Thanks. that could be the ticket.