I have been following this thread for a while now and was waiting until I could consider myself a successful mandarin owner before I posted anything.
I was very excited because my mandarin and I were approaching our 10 month anniversary together and, from what I have gathered, people in the reef world generally say that if your mandarin is still plump and active after a year, you can consider yourself to be a successful owner. My tank is only 65 gallons, but I have a 30 gallon sump/fuge and a whole lot of live rock, and I also set up several rubble piles in my display tank several months before I went out to purchase my mandarin. It was a good thing to because, even though I tried and tried, my mandarin never took to prepared foods. Regardless, nearly 10 months in I was feeling pretty good because my mandarin was plump and my pod population was still high.
However, my mandarin decided to celebrate our 10 month anniversary by carpet surfing while I was at work. His death was upsetting on many levels. In the two and a half years that I have had my aquarium, my mandarin is my first fish loss (I have had cleaner shrimp mysteriously disappear, but nothing else has kicked it). Also, I felt bad for the poor little guy. Suffocating/drying up cannot be an enjoyable way to go. And then I was also kicking myself because it had just so happened that I had forgotten to put my egg crate back on to the aquarium the night before after I'd been doing some take maintenance.
Alas, I am not meant to be a successful mandarin owner. I have not yet decided whether or not I will purchase a replacement for my little guy. I loved watching him swim around the tank. I think, out of all of my fish, he had the most character. However, I was constantly worried that he would exhaust his food supply or that my clowns or damsel would bully him (which they probably did, causing him to jump in the first place). Even though I seemed to be on the right track, I feel like getting another mandarin might be irresponsible because I still can only speculate that my tank's pod population can handle one.