I have been looking at this as an option for my reactor and wanted to know if anyone else is using it. It's kind of pricey, $60 for 600g, so I wanted to see any reactions there are to this stuff before I drop that much money. In the mean time I am just using plain old GFO. The GFO takes care of phosphates but the Katalyst is supposed to take care of phosphates and nitrates.

http://brightwellaquatics.com/products/katalyst.php