I acc just received my ORA mandarin slightly over a week ago, and she is great. They dont lie when they say they are one inch. She is only slightly bigger than my thumbnail! I was at first afraid of her starving, because everyone told me it couldnt be done, but its working out great. The best news was when I first decided to feed her tiny bits of frozen brine, and she ate it! I was so happy, because i knew now that she wouldnt only have to eat pods! Plus this makes it so much easier. I put her in a breeding box because my clowns could tear her in half, my torch coral and nem could easily eat her. The box is absolutely stocked with pods though! I dose everyday just to be sure, and theyre always in there.
For your tank, even though it is a 45g, I would suggest getting an ORA mandarin: they are more expensive, small, but worth every penny. I would suggest you add some pods, maybe wait about 2 weeks, then order an ORA mandarin, with like 4 bottles of pods and some phyto. Give the mando a few days before you try feeding it frozen though. If the mando is very small, get a breeding box like i did. YOu can add small squirts of the pods daily, and you can just either put pods in a fuge if you have one, or just leave the bottle caps open so they can get oxygen, and leave em in the bottle. Once the mando is big enough, put her in the tank.
Best of luck to you, great choice, mandos are beautiful.