Seio powerhead magnets

[mseepman]

Yikes...anything rusty looking can't be good for the tank.

[Snappy]

Yep I'm sure it causes problems.

[Delphinus]

Meh, you can dose iron, this just means you get to dose less.

Those Algae-Free magnets eventually lose their seal and this happens. Brad had a good point though: just switch sides on them and get another year out of them. Although maybe don't wait until it gets to the point in the picture.