Algae?

[supercichlid]

Hey guys.
My lfs have given my a big long list of marine fish/inverts etc that i can order. On the list, it says i can order algae..there are three types i can get:
"Caulerpa Stones
Green Fern On Rock
Grape Algae"
What are the benefits of having these algaes in tanks? In FW we try to get rid of algaes..in SW we try to keep them?!
Please explain.
Thanks
James

 

[striker]

Plants and algae are important factors in the biological filtration of a sw tank because they will reduce nuisance algaes (by competing with them) help with lowering nitrates. The only problem is that some plants can grow out of control and you will have to begin trimming them after a while(caulerpa). Many collectors keep the plants in their refugium so it doesn't grow out of control and is not eaten by fish. It also depends on the plant you buy for the tank. Money plants for instance are difficult to keep alive if your tank is low in calcium. Check out different sites for info on plants and which will be best suited for the aquarium.