ok, if your tank is matured then take a piece of LR from your tank and place it in your refugium, this will jumpstart your pods in the refugium...that is if there are pods on your LR...then get some culerpa, doesnt really matter what kind... make sure you've got some LS or miracle mud in there...
and i would make sure you've got a a large enough pod population to support a manderin...
i personally want a manderin for my 75 but i'm gonna wait a year or so to get one, maybe more...just to be sure that i have enough food for the little bugger...
also, you can start by putting "pod piles" in your display tank by piling rubble from LR in a corner or somthing and then when you do get your refugium put those piles in there...