There are places you can buy pods, all over the net of course and some LFS carry Tigger Pods in a little bottle. I've ordered pods from ipsf.com and from a seller on ebay and both were amazing and really have my refugium and tank hopping with little buggies. ipsf.com has a really amazing 9 for $99 deal where you can pick from a menu and get 9 items shipped for $99 total. Get the pods, live sand activator, miracle mud and some of all the macros they offer, plus the "pod mat" which is just sea lettuce, but the pods do love it.
The one I found on ebay is called piece-of-the-reef and I am really happy with them. I got "1000" pods (they can't really count them, but they give you enough to know there have to be that many or more) from them for $28 shipped. They arrived in filter sponges in a ziplock baggie. I just shook out the sponges one at a time until nothing else came out of them and then tossed them. There were at least 2 different types of pods and it seemed like a zillion of them came out of those sponges.
I have a green spotted mandarin and he started out at 1" and has grown at least 1/2" in the month I've had him. He's gaining weight and his tummy is always round and fat. He is also taking bloodworms, frozen vitamin enriched brine, ground up freeze dried krill (I use a mortar & pestle) and I mix up the foods in a random mix every day, twice a day and soak everything in a vitamin soak and either roti-feast or phyto-feast. My Scooter Blenny eats all those too. I use a turkey baster to make sure I put food where they can get to it and I turn the pump off while I'm feeding so it doesn't all go down the overflow before the fish and corals have a chance at it.
From everything I've read and my limited experience, try to find a mandarin that is small - not skinny, but just as young as possible, because they're going to adapt to tank life better and are more likely to start eating prepared foods. Also, it seems that the psychedelic mandarins are more sensitive than the spotted or target mandarins. I don't know this as a fact, but I brought home a psych mandarin several months ago, before I had my scooter blenny, I knew I had plenty of pods in the tank and was prepared to buy more to add in. He didn't make it through the night. I know he'd only been at the fish store about a week before I bought him and in hindsight, I didn't watch him for long before I just said "I'll take him!". I waited on my spotted mandarin till I knew he had been at the store for about a month before taking him home. He was active and eating when I visited him at the store.
gotta go, kids are screaming! Hope this helps!