Unless you get one of the ORA tank raised gems, or one that just happens to take to prepared foods you need to have a large system with a heavy pod population or they just wont make it.
One thing I've also learned since I have tried keeping two now. The big pods you can easily see and find with the naked eye aren't the ones they are looking for. I've found that they are usually after the smaller hard to see pods; like tiger pods. I went ahead and let my tank age another year before trying again and now I've had a gorgeous specimen for over 3 months but I'm concerned that even now he may not be getting enough food. My system is about 300 gallons in total volume with tons of rock, sand, and chaeto so I've gotten in the habit of shaking my macro algea over the main display area to make sure the pods from the sump are making it up to the main system.
In all honesty if your take is less than 200 gallons I wouldn't try it but I have seen Mandarin's make it in smaller systems.