Fighting Algae for months

[rkrgk]

Thanks Jwhouse.
So I added 4.26Gal of bleach again yesterday. I tested before adding the bleach and my FC was 0 (remember I had 4.0 ppm in the morning). CC was 1.0ppm
After adding Bleach and brushing
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FC - 14
CC - 1.5
Tested this morning, I took only at 7:15 am, so sun was up for few minutes, but pool is at the north side of my house
------------------------
FC - 9
CC - 1

BTW, is CYA difficult to dissolve. I see mentions in posts about using a sock to put in front of the return?

[Watermom]

Keep hammering it with bleach and yes, you can put CYA in a sock in front of a return. If you squeeze the sock occasionally, it will dissolve faster.

[rkrgk]

Thanks Watermom! I will do that.
And checked the Cl level again (11:30 am) , its depleting very fast in sun.
FC - 3.0 (was 9.0 at 7:30 am)
CC - 1.0

[rkrgk]

I am not really sure what it is, but I am a bit freaked out about it now..
I was running my hands on the pool walls, and I can feel graininess. Its like when I run my fingers some small grainy/sandy substance comes out. When I look closely I can see white granules coming out of the wall as I run my fingers.
What is it? Is it calcification? or is it that some substance is corroding the walls and what is coming out is part of concrete?
There is also powdery substance at the bottom of the pool and the pool steps and when I brush they just come out and make the pool cloudier.

[Charlie_R]

I would think you would need to check your pH and Calcium hardness. It MIGHT be your plaster eroding. But I don't know.

[rkrgk]

My pH is 7.3 and CH - 400 (I tested 3 days ago). Can it be the plaster eroding?

[rkrgk]

Ok, I did some more checking, and seems like there is a layer of white powdery substance on top of the decorative tiles as well (which lines the top edge of the pool walls). It comes off if I scrub bit hard. That makes me think it could be calcification? Can 400ppm of hardness cause calcification?

[PoolDoc]

My pH is 7.3 and CH - 400 (I tested 3 days ago). Can it be the plaster eroding?

It's not plaster erosion (or dissolution), with a pH of 7.3 and CH of 400. It actually sounds like sand algae residue, which usually appears as small particles of calcium carbonate that look like sand initially, but bleach to white.

You can test it easily enough. Make an acid solution, by dissolving 1 cup of dry acid in a cup of warm water OR by mixing a cup of water with a cup of muriatic acid. While wearing plastic or rubber gloves, immerse a sponge in the acid solution. Without squeezing it out, rub it or hold it against the granules. If it's sand algae residue, the particles will fizz and dissolve away.

-- DO NOT DRIP ON YOUR DECK -- DO PRACTICE ACID SAFETY -- READ THE MURIATIC ACID GUIDE IN MY BLUE SIGNATURE BLOCK --