I have mermaid's fan. I got two of them, and they have sent up about 5 new shoots already. Fairly slo growing, and they do require calcium, but they're very pretty.
GCE is a good source, as Flreefer already stated.
True plants are few in the marine aquarium hobby. There are some seagrasses that can do ok, but they are very slow growing, require at least 6 inches of sand, and recover from having their roots disturbed very slowly. Macro Algae is the way to go.
I have quite a few, if you have more specific questions.
I have three types of Caleurpa, Halymenia, Gracilliara, Halimeda, Mermaid's Fan, Shaving brush, Pinecone, and C. barbatos.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef