Was it dust, or yellow algae?

[AZPoolDad]

I just finished a total drain and refill here in Phoenix. After a week I have everything balanced out, the CYA up to 50, pH is 7.6, and water is crystal clear. However, when the pool was totally empty and dry, I washed down the walls of the left over "dust" that I was having a hard time vacuuming/brushing out of the pool previous. I was convinced I had a lot of desert dust settled in my pool the last few months, but now I'm thinking it might have been yellow algae. When it was dried out and swept up into a pile in the bottom of the pool, it looked like a light brown and VERY fine powder, almost talcum powder in consistency. Since it was hard to brush up and vacuum (it tended to stick to the PebbleTec), I'm now thinking it may have been yellow algae instead of dust.

Thoughts? I wish I had kept a sample. Maybe it could be tested somehow.

 

[danjaymor]

Hi, APD....I'm in Mesa. I'm no expert on yellow algae, but we certainly have no shortage of dust fines that resemble what you described.......I've been pulling up what you described in my pool cleaner all week.....

 

[chem geek]

Yellow/mustard algae prefers shade so if the dust was mostly on the shady side of the pool then it could have been that algae, otherwise it's more likely to be pollen or similar colored dust. Yellow/mustard algae can hang out behind light niches and under removable ladders. If you instead use a skimmer sock and collect this yellow substance there, then it's less likely to be algae.

 

[AZPoolDad]

Okay, since my pool gets mostly full sun, and the "dust" was widespread, I guess it wasn't yellow algae. There was a lot of it that wasn't getting picked up by the vacuum however, and even though I brushed a lot it wasn't going down the main drain.