As awestruck wrote there are two types photosynthetic and non-photosynthetic. The photosynthetic gorgonians are fairly easy to care for - good light and nutrients in the water column and that is about it. The non-photosynthetic are extremely hard and most do not live long in the aquarium. I have a species tank of non-photosynthetic gorgonians and a very large tank, this is about the only way they can get proper care without polluting your tank (They take constant feeding).
So if I were you I'd get the photosynthetic gorgonians first and if you really like them then try a non-photosynthetic species - both are beautiful IMO
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