We finished our pool in the beginning of October last year(2011) so it has been up and running for about 9 months now. We recently had a little trouble with some algae. It was either black or a dark green sand it seem to be under control now. The guy at the pool store said I should buy a stainless steel brush, but a different pool guy said not to use stainless steel. So now I am at a loss for what I should do. I did buy a Whale Wall brush just because I heard good things about them and thought it would be worth the extra money.

We have dark gray plaster and it has black and white quartz sand in it. The surface is gray in most areas, but some areas you can see the quartz. I would really like to bring out the quartz so it would even out the colors a bit. I was told we could do an acid wash by either draining it, or without draining.

So I was wondering, could I just use a stainless steel brush to clean the top thin layer of plaster to show the quartz underneath, as well as removing the stains left behind from the algae? I don't want to ruin my plaster by using a brush that should be used, but I also want to take care of the algae, and be able to see the quartz that we paid for.

The usual rule is not to use stainless steel during the first year. Regardless, brushing, even with a stainless steel brush, will not explore the quartz sand in the way you want.

The algae stains will go away slowly with elevated FC levels. To expose the quartz you need to do an acid wash, either a no drain or regular drain acid wash.

I poured some powdered shock into the deep end right over the stains and much if it landed and sat right on the stains until it dissolved. That removed most of the stain. I guess I will just do that a few more times.