You can grow whatever types you like depending on what you can get your hands on. It has been my experience that "green" macros grow much faster than "red" macros, and thus I would assume the green algae is better if you are looking to achieve nutrient export. I grow some red macros too just to harvest to feed to my tangs, but I have never had good luck getting strong growth from it.
I really like Chaetomorpha , sometimes called spagetti algea, if you can get some. It grows fast, tangs love it,has never crashed on me, and it's growth form provides a nice refuge for breeding pods.
I started my refugium with just caulerpa, but whenever I visit a reefer with something I don't have, I ask for a handful, just because I like variety.
