Is a DE filter better than sand for iron removal

[smallpooldad]

In an ongoing fight against iron in solution in the water, carried into it by airborne red dirt (ferric oxide aka rust), I was wondering whether a DE filter, as it removes particle down to 2 microns, would be better than a sand filter? Or is the soluble iron even smaller than 2 microns and would just flow straight through the filter? If DE is appropriate, what size would be good for a 9,000 gal pool?

Looking forward to your replies.