I don't think you need to wait that long to add a mandarin.I waited two months before i added mine.that was 5 months ago and mine is fat and happy.The key is making sure you have an active and plentiful pod population.I started with very good liverock that had alot of life in it.within two months i had a great pop population.If you start off with dead rock that you cycle you will have to wait along time and introduce pops before you get a decent population.The best thing you can do before setting up a marine tank is read,read and read some more.Go visit some tanks if you can,then do some more reading and then when you have done that,read some more.see the pattern here.
my fat mandarin. 8)