There are not many Gorgonians that I would ever suggest keeping in captivity as they often don’t have a great survival rate. One of the exceptions to that rule is the purple sea blade also known by the scientific name Pterogorgia.
Pterogorgia is beautiful Gorgonian that is often found in a stunning purple color with white polyps that will often extend well beyond the tissue. It is easy to identify as the branches look like they have been flattened and the polyps do not occur all of the way around the branches but only along the edges of the “blades”.
Captive care is similar to many other corals. I have personally had success with this coral under VHO’s, Power Compacts, T5’s, and Metal Halides. I would say that VHOs and T5s resulted in the best growth rates. Make sure you keep a stronger but interrupted current on this coral and keep other corals especially SPS upwind of Pterogorgia. It regularly sloughs off an outer layer of tissue which should be removed from any corals that it settles on. As a rule Gorgonians can be pretty toxic to stony corals (pretty much all corals have some way to defend themselves). So just make sure you give it adequate space.
Feeding and care are really not something I have had to really spend a lot of time on. I have seen the polyps catch fairly large particles of flake food, frozen food, and detritus when I stir it up with the old turkey baster. If you don’t have one it is a great way to stir things up when you are cleaning your tank.
Propogation of Pterogoria and all Gorgonians is very easy. You can cut it with a razor blade or small scissors. The center is going to look like and feel similar to a stick. You can then take out a small rock and superglue the Gorgonian or attach the branch with a zip tie if you can find a small hole in the rock.
Share a frag with your friends. If for some reason you have trouble with it maybe you can try again if your friend is successful. I have maintained these Gorgonians in nearly every tank with great success. Keep an eye on fish that are notorious “pickers”. I have seen an Algae Blenny really irritate it as well as a Flame Angel. While this may not lead to the death of the coral the lack of polyp expansion interferes with feeding and may ultimately lead to infection or tissue damage which can give algae a foothold. From time to time you can blast off the coral with your turkey baster which will knock off any loose tissue as well as cyanobacteria before it can become an issue.