I use Phosar HC in a 2 little fishes reactor, & my phosphates stay between 0.01 & 0.024. As long as you start very, very, very slow when first using it, it works great for a long term solution. It should be introduced over a 2 to 3 month period in small amounts to give your corals a chance to adjust to the lower level of phosphates.
As for that product, it didn't get Randy's "stamp of approval" at RC, so it doesn't go into my tank.