Help with plaster spots

[myapaws]

My plaster pool is covered with these spots and markings. They range from white to yellow to black and grey. They are all over the floor and the walls. I have scrubbed with different brushes and nothing happens. Is it algea and etching or calcium buildup? What options do I have? I have used Scale Tec and Magic Jacks Iron solution and neither worked. The pool looks really bad - i know the pics are hard to tell..Any help would be appreciated!
FC -4
Cc-0
TA-70
Ph-75
CH-275

I am runnings a SWG.

Thanks

 

[pooldv]

What is the finish? Plain colored french gray plaster? When was it plastered?

 

[myapaws]

The plaster was done about ten months ago and it is supposed to be deep blue.

 

[onBalance]

Check out this thread for some possible causes. Diagnosing Pool Plaster Problems
Look at the section on Whitened Discoloration of Colored Plaster.
Also, it may be that there are two issues, one is from improper troweling during original plastering work, and the other is a calcium scaling issue.

 

[ryan-california]

Did this just start or has it been like this for a while? Looks to me like it could simply be poor brushing and "plaster dust" that has hardened. I have an area that I didn't brush well on our pool that looks similar. I am slowly working it with the brush and fine sanding, it's starting to look great