I have been having some issues with PO in my aquarium and have determined it is mostly caused by recycled LR from my lfs. My other levels are good and we are working on reducing PO. I thought I would give a GFO a try and wanted to make sure I had the right items and media for a combo gfo/carbon setup.
http://www.bulkreefsupply.com/brs-gfo-carbon-reactor-dual.html
http://www.bulkreefsupply.com/brs-bulk-premium-rox-0-8-aquarium-carbon.html
http://www.bulkreefsupply.com/brs-bulk-gfo-granular-ferric-oxide.html
http://www.bulkreefsupply.com/brs-gfo-carbon-reactor-dual.html
http://www.bulkreefsupply.com/brs-bulk-premium-rox-0-8-aquarium-carbon.html
http://www.bulkreefsupply.com/brs-bulk-gfo-granular-ferric-oxide.html