Hi,
Mandarins are not hard to care for at all, I'm sorry if you feel discouraged. There are in sump refugiums, and CPR makes an in-tank one, large and small... I have one and it works great. You can also have another small tank that can be converted into a refugium.
I personally do think a refugium is needed to keep one, because they deplete the pods so quickly otherwise and run out of food. Some folks managed to teach theirs to eat frozen foods, but I wouldn't count on it as a way to keep one.
I know, I was planning on getting an HOB refugium but I don't know if they can sustain pod populations. Buying pods is a little too expensive, more expensive than the fish. I not sure if I can train it, or if I should take the risk and get it. What do u think? I know I need a developed tank and I wasn't planning on getting it for a long time. My tank is only 3 weeks old and I hav plenty of time to think.