I woudl gt a good phosphate reactor such as phosban, which are very inexpensive adn will do a great job.
Word of advice though, many people have had a really bad experience dropiing theri phosphates too fast and causing damage to theri corals.
I run PhosGuard in my canister filter per directions / amount, and change it monthly. Never tried any of the Iron Oxide Hydroxide yet, can I do that in the Fluval like PhosGuard or do I need a reactor? If so can I run THAT off the Fluval? :)

Isn't the Iron Oxide Hydroxide stuff supper fine? Place it in a mesh filter bag then?
How about it's replacement timeframe, any leach-back?
And I assume it's better for the tank them the Aluminum based removers (PhosGuard ect.)?

I don't keep Leathers, and don't intend too, I want to stick with SPS / LPS.

Different brands are different, but my normal Magnum basket holds many GFO brands just fine. It is a better choice than aluminum-based materials, but all have their issues, as mentioned in the article.