The crust of the Earth (where the oceans are located) consists mostly of
silicon and oxygen. Iron is a small percentage, less than 10% I think.

"George Burnt" wrote in message
...
According to what I've read, the iron content in our aquariums should be
almost nil. When I lookied up what it is in the oceans, it was almost nil.
(0.000006 ppm).

Well here is my question for all you geology/chemist brains out there.

If the earth is made up of mostly iron, should there not be a high iron
content in the world's oceans? Why isn't there?

And that is my question of the day.

I am just curious, it is not important for my tank, as I don't even test
for
iron.

GB