>> I'm wondering whether I should do the same thing vgg659 did?

Absolutely. But, don't forget what I did.

1. First, I brushed and brushed.

2. Then I treated with elevated chlorine levels. Pretty standard advice on this forum.

3. Then, I got my water tested for metals (well, I tried, but the pool store was closed).

Since I had to wait the holiday weekend for the store to open, and I already had a quart of Metal Out, I dumped it in. I haven't done any maintenance treatments lately of Metal Out, so I figured it couldn't hurt.

4. Since I had already treated for biological stains (elevated CL), and nothing happened, and my stains responded to the Metal Out treatment above, I treated for a metal stain even though my water test (sample taken prior to Metal Out treatment) ultimately showed no metals. I used 4 lbs of Stain Out and 2 qts of Metal Out to treat my 25,000 gal pool, following label directions. By the way, following label directions is important when dealing with metals and chlorine.

So, begin at step 1, and I'm sure that you'll do fine. I'd be particularly interested in the results of your water test.