If you are going to get a mandarin, I would wait 6+ months or so and have a healthy fuge with lots of macro. Then seed the tank a couple of times with tigger pods and also make sure you dont have fish that over compete with them for the pods. Also make small piles of live rock in the tank and sump where they are protected from predators. The more established your tank, the better luck you will have. If you still wonder if they will survive, then the answer is probably no. Also watch out for flatworms, they will decimate a pod population. Be patient and keep other fish for a while. Let the mandarin be one of the last things you add.