I tried two different sebaes...and twice they died within 4 months. The first was pure white with purple tips...the second was bright yellow. I have since read that the pretty ones are the least likely to succeed in an aquarium (even if you have the perfect setup), because they have expelled their symbiotic algae, and have a hard type uptaking it once it's gone.
Whether that is true or not, I don't really know. I just know that I will not be killing anymore sebaes, because I will not be getting anymore sebaes.
If you must try an anemone, try a bubble. They are much hardier, in my opinion. Mine burned itself on the heater, looked like it was going to die, then made a startling and robust comeback.