Quartz Plaster has Tiny Black specs/dots - is it black algae

[Treetopp]

Quartz ivory plaster 6 months old. I see these tiny black specs/dots on my pool plaster. Seems like more keep showing up or I’m just paranoid.

i’m thinking it’s just some dark pebbles in the quartz aggregate but would like your opinion. They don’t come off with brushing and I’ve put a chlorine puck on some and they don’t change. I‘ve even taken a pointed metal skewer to try and scrape them and nothing comes off. Pool water is crystal clear, never been cloudy. I maintain the pool levels according to Trouble Free Pool guidelines and use the recommended test kit. Salt water pool.

I’ve attached some pictures.

 

[Bperry]

Quartz ivory plaster 6 months old. I see these tiny black specs/dots on my pool plaster. Seems like more keep showing up or I’m just paranoid.

i’m thinking it’s just some dark pebbles in the quartz aggregate but would like your opinion. They don’t come off with brushing and I’ve put a chlorine puck on some and they don’t change. I‘ve even taken a pointed metal skewer to try and scrape them and nothing comes off. Pool water is crystal clear, never been cloudy. I maintain the pool levels according to Trouble Free Pool guidelines and use the recommended test kit. Salt water pool.

I’ve attached some pictures.

I don’t see anything wrong. Maybe add an arrow?

 

[Rocket J Squirrel]

I think it's your quartz, i.e., the finish you chose. Why do you think it's an issue or even just a surprise?

 

[Treetopp]

The tiny black spots circled in red. I’m probably being paranoid but I’ve heard such terrible things about black algae and it seems like there are more and more of them as time goes by. I don’t remember seeing all these black dots right after the quartz plaster was finished.

 

[Rocket J Squirrel]

It doesn't look like algae to me. Post your full water chemistry readings. Do you have a good test kit?

See Test Kits Compared

 

[Treetopp]

I use the TFT test kit for salt water pools recommended on this site. Could there be some metals or something mixed in the plaster that is turning black?

most recent chemistry level
Free Chlorine - 6 ppm
pH - 7.6
Alkalinity - 80
CYA -70
Salt - 3300 ppm

 

[Bperry]

The tiny black spots circled in red. I’m probably being paranoid but I’ve heard such terrible things about black algae and it seems like there are more and more of them as time goes by. I don’t remember seeing all these black dots right after the quartz plaster was finished.

Doesn’t look like black algae to me.