what kind of planktons do you feed? Most gorgonians & carnations do very well under low light but they need to be fed. They can also be problematic because of their low survivability rates. I think thats because there low light, from deeper waters, and dont get the necessairy pressure that they need to survive in an aquarium but thats just my theory. If you dont feel like feeding planktons, at least not a ton of them, I would go with mushrooms, xenia, maybe star polyps even thou lots of books say some prefer higher light, or just try out other inexpensive softies. Other than that your pretty limited but that can be a good thing because then you get creative but with creativity comes success and failure, expect both.