What is GFO
 

Hi Everyone,

Just wondering what GFO as I kinda know what it is and wondering what you would use it in? And how would you use it?

Thanks for any info or links so I can learn about it.

Granulated Ferric Oxide
here is some reading.Quite informative.Most people use it in a reactor with tank water penetrates one end tumble the GFO at a slow rate and returns to your tank.
GFO