Ryan has since edited , as he states he was not aware api had a marine algaefixHe is unaware that there is a marine version of Algaefix. As far as I know, the only difference is the label, the contents are identical.
This is interesting. The label says "When used in salt water will not harm snails, clams, scallops, shrimp, anemones, sea cucumbers, feather dusters, coralline algae, soft corals, hard corals, and other invertebrates".