Are they difficult to raise?
It's not hard just very time consuming and you must learn how to raise aptasia. You have to monitor the nudis (under a scope) and once they are aptasia eating size you have to cut up tentacles. Daily water changes because you can't use any mechanical filtration. They are very sensitive to temp. change, so a controled environment is needed.
I used to crate them home from the lab but found that the house was too cool and growth was arrested or at least slowed considerably.