Visible Algae or Dust/Pollen?

[JibJab]

I know this topic has been covered many times, and I have spent a long time reading numerous posts on the forum, only to be banging my head a little...

This may sound incredibly stupid, but how do I know if I have visible algae, or is it just dust/pollen? I've attached photos.

Reasons I believe it may be algae: It tends to accumulate along the vinyl seams, it clings to the walls (though, the walls are slanted)
Reasons I believe it may be dust/pollen: DFW is a dusty area, there's frequently dust on the pool surface (see attached photo of the skimmer sock), there's no difference in accumulation in sun vs shade, the water is clear.

Anyway, the question is if I need to SLAM. I've passed the OCLT, have CC's below .5, but do I have visible algae??

FC 5
CC 0
pH 7.6
TA 50
CYA 40

Note in some of the photos, the "line" between the 'clean' vinyl and not is where I ran my feet while swimming. It just 'clouds' up in a poof and is gone

 

[YippeeSkippy]

If it lands anyplace else like your car, patio, etc ....(in Georgia it's famed for being yellow as we have pine trees galore) it is likely to be pollen.

If in doubt though, running an Overnight Chlorine Loss Test will help you decide-
Overnight Chlorine Loss Test

That schmutz on the filter sock looks like dust, dirt and debris to me actually. The pool looks like algae though.

Maddie

 

[mariane]

I second YippeeSkippy

 

[JibJab]

Thanks for the replies. So, I did run the OCLT, and passed it. This would be the biggest reason I am uncertain.

You both say it looks like algae... this is from your experience? What can you point out to me that makes you think it is? I guess what I'm asking, is what makes you think it's algae over dust/pollen?

 

[YippeeSkippy]

Just the wide swath of <something> on the pool. Is it on the deck or furniture also?? You passed the OCLT, so I guess it could be dirt/dust.... are you brushing often to get it into circulation so that your DE filter picks it up?

does it reappear and how fast if so??

Maddie

 

[mariane]

Also, if you try to vacuum it and it "poofs" away in a cloud, it's dead algae.
I guess I've never taken pics of the dead algae on the bottom of my pool. Let's just say I've had my fair share.

If it's stubborn and sits there when you try to vacuum, it's sand or dirt. I've had that too - polymeric sand from the brick deck.

If you see it on other things, a ring around the walls at water level, it's pollen.
This early summer when I saw yellow powder around the water line of my pool, I thought someone had been spraying something, like fertilizer (which made no sense) in my pool. Then I noticed it was on the top rails, the patio set, the vehicles in the driveway (which are not close to the pool) , etc. Thus, pollen.

 

[Rancho Cost-a-Lotta]

it clings to the walls

This too. Does it feel slimey?

 

[JibJab]

A lot of great feedback from all of you! Let me answer your questions.

YipeeSkippy: I honestly have not noticed it on other areas... and so I will do another OCLT for double verification. I haven't brushed as recently as I should, but more because I'm observing the <mystery>. I vacuumed maybe 2 weeks ago, and it came back mildly after 2-4 days, and back totally after perhaps a week.

Mariane: When I vacuumed it, I sucked it right up. I could see exactly where I missed it on some of the angled walls. Had I brushed instead, it would have poofed into a cloud and remained, and made the pool hazy for a few hours until it resettled. I've also noticed a pronounced color difference in the returns, right at the water level, as though the <mystery> has been staining it.

Rancho: It does not feel slimy.

I think I might just SLAM the pool, almost as a way to just move on with my life, LOL.