Check out some of the on-line sources, this one here may offer some different macroalgaes. I've run several over the years; currently running two; grape caleopa (sp.) and other calcerous algae from the Atlantic that I can't remember the name of, but it kind of looks like dimes attached end to end (I'm pretty happy with it, not as aggressive as the caleopas) Definitly don't recommend the fern-like one, it goes through cycles of massive growth and massive death, ends up polluting your tank with nutrients. Sorry can't be more specific, but don't have my books at work - they're at home (I'll look for names and repost tomorrow if no one else chimes in with names)