metal(maybe iron) in water, harmful?

[mikemou]

Hello~
I have a nice decoration piece that I want to put in my 55gal., but it's made of some kind of metal(I think iron, not sure). If I strip out all the rust cleanly before adding it to the water, would there be known harm to the fish?
Thanks!

 

[QTOFFER]

I really wouldn't risk it.
At best, it would probably throw off your GH; at worst, it may harm your fish and plants.
And don't forget that many cast-iron and non-stainless steel pieces often contain other metal contaminants.

 

[TankGirl]

Heavy metals apparently break down the slime coating and can destroy gill tissue (according to Baensch), which produces respiratory problems, naturally. Any kind of metal is to be avoided in a tank, and you even need to keep this in mind when using rocks to decorate, since they often will contain a vein of iron, or other metal.