I brewed two batches of beer with water that had a minimal amount of iron in it and it gave the beers I made (Weizenbock & Belgian Dubbel) a very funky off-flavor. Admittedly, the funk went away after about 6 months, but again, the iron in my water was minimal, and did not look anything like yours. I would not use it ...
Es freut mich mit Euch Allen brüderlich zu trinken ! Ein Prosit der Gemütlichkeit !