Gorgonians need to be anchored firmly onto the rocks, in an area of diminished lighting, and enjoy frequent small feedings. Many gorgonians can not be kept successfully in aquariums that lack of suitable food. Also avoid putting them into tanks with lots of mechanical filtration, since this will filter out their food before they have eaten their fill. These two groups are distantly related, but share a common need for sandy substrate. They should be placed in a part of the tank with at least three inches of sand.
Tube anemones are voracious predators that can expand dramatically.
Feed them about twice a week when they are fully expanded. Sea pens are totally harmless, and require strong unidirectional flow, diminished light, and frequent liquid feedings.