Is this what you used?
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=13963&Ntt=phosphate%20medi a&Ntk=All&Ntx=mode+matchallpartial&Np=1&N=2004&Nty =1
Looks like a good product. I use iron based phosphate removal media too. Although I have read that you should slowly begin using it because it can 'shock' some corals. It may also reduce alkalinity; check your alkalinity and PH.