Fighting Algae for months

[Charlie_R]

Then it probably is calcification. I've seen here on the forums where the mods talk about what level of CH works best for your type of pool, just don't remember where it's at here. There are apparently many factors involved in scaling, and I'm not experienced in gunnite pools. I was just trying to help the mods with a heads-up on what your levels were. Sorry I can't be of more assistance.

[rkrgk]

No problem, Thanks for taking time to reply.

[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 --

[rkrgk]

White Algae? Wow!! I think my problems are moving into a new course? But thanks a lot Ben, its a lot of help just identifying the problem itself.

So, what is white Algae? Yes, it looks like calcium carbonate , when I squeze it, it just turns to powder and dissolves. I tried to test it, but could not test with certainty. I tried to scrub the wall with the diluted acid solution, just like you told, but when I put in the pool, I can not really determine if it frizzes and dissolves.. may be the sponge gets drenched in pool water and makes the acid very diluted.
I have this quite a lot in the pool bottom I think. When I brush specific parts inside the pool, a lot of brown powdery substances come up and some other places its white powder..My filter doesnt seem to be catching any of these stuffs.. I dont know if my filter is working well or not!

I attached a picture of the pool wall and the whitish cloud that comes up when I brushed the side.. please let me know your thoughts, Thanks!

[rkrgk]

Update..
My pool was cloudy no matter what I did, so finally I decided to change out all my filter grids. So I did that last week and viola.. water is clear after about 24 hours of running. The pump. Still there are lot of debris at the bottom but I guess I can vacuum it out
Thanks again for all the help this forum provides..