Not to rain on your parade even more...
But a Mandarin is not a good choice for a tank that size. It need a much bigger system with a nice big fuge pumping out tons of pods.
Bottom line is , your system will not be able to produce enough pods to keep the mandarin alive. Take it from me... I was an ass and tried. However, when I bought mine it was eating prepared foods.. dont' let this excite you and think "oh its eating prepared foods, lets take it home" Because as soon as you do that... and the fish is swimming about your live rock, it notices it's natural food source (pods) swimming around and then takes to those. That's what happened with mine.. it just flat out stopped eating mysis .
I know how annoying it is to want a certain fish and not be able to keep it, or have people tell you what you can and cannot keep. Just keep in mind.. we're trying to save you hassels and problems that will come later. It's all for the best, trust us
Cheers