White Algae?

[TXFlyGuy]

[attachment=0:b7u8knkz]110_4016.JPG[/attachment:b7u8knkz]Is there such a thing as white (gray) algae? I have a few spots on my pool bottom that are growing in size quite fast. One spot is nearly a perfect circle 2 foot and seemed to appear (bloomed) overnight, while the other areas are oblong / rectangular in shape and seem to getting larger. Brushing and acid seem to have zero effect.

In the photo (midway dead center between the tanning ledge and two drain intakes) is the circular white/gray patch that just appeared out of nowhere...almost overnight. It's a little hard to see because of the glare.

At first I thought this was plaster dust and/or scale. Now I do not know what it is!

water test-

FAC - 2
pH - 7.4
TA - 80
CYA - 45
CH - 280
SALT - 3300
Phosphates - 200

Test done by Leslie's

 

[Melt In The Sun]

A picture would help immensely. Your FC is on the low side, so I would bump that SWG up a little. Nothing looks horribly wrong with your test results, though it would be much better to have your own test kit than relying on Leslie's.

 

[TXFlyGuy]

OK, these show the white/gray circle that showed up. Before, this area was perfectly clean as we had just completed the no drain acid wash. This is about 2 feet in diameter and is surrounded by the darker area which is what most of the pool looks like. You can see a few other areas as well. These all seem to be growing in size.[attachment=0:1i9ipoz7]110_4019.JPG[/attachment:1i9ipoz7]

 

[duraleigh]

It is VERY unlikely that is algae. My guess is it might be the pool surface getting cleaner by removing another layer or some residual of whatever the reason was for the acid wash.

Why did you acid wash it?

 

[TXFlyGuy]

It is VERY unlikely that is algae. My guess is it might be the pool surface getting cleaner by removing another layer or some residual of whatever the reason was for the acid wash.

Why did you acid wash it?

Long story...a pool company was hired to do some tile grout repair on the spa dam wall. Spilled a HUGE amount of grout and he allowed it set up on the pool bottom right in front of the spa. Then an unknown quantity of acid and scale-tec was added. It got rid of the grout from the pool bottom, but also cleaned up a lot of other issues I had, i.e., residual plaster dust and/or scale. Note: the original start-up was not done properly, very little brushing at all.

I then did the acid treatment in hopes of making the rest of the pool regain a uniform look.

Previously the plaster (Stonescape Tahoe Blue) was almost robin egg blue in appearance. And there were a few tiny random spots on the bottom that were very dark gray, almost black. These spots were the size of a quarter and started appearing over time in patches. After the acid treatment, these spots disappeared, and the pool dramatically changed color going to a very dark emerald/turquoise blue. It is now very pretty.

But there are these few white/gray patches left that I'm trying to remedy. And oddly enough, they are growing...either that or the dark and very clean plaster is somehow shrinking away. The tanning ledge is picture perfect, and is the only place in the entire pool that looks the way it should.
Here is a photo of the tanning ledge...