Possible copper stain, less than month old pool

So we have a new pool, above ground, that has been filled for probably just about a month now. I've been following the TFP method, and we've had great results with water clarity. But we're starting to see a brownish greenish ring around the water line and just below the water line. I've scrubbed the Crud out of if with very little effect. The pool was filled with water from the house spigot/hose. I did look up the village's water report and found the report from 2020 saying they found 1.2...

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