mantis - I know... everyone I talk to says that triggers in gerneral are bad news for a reef... nigers included. When I first set up my tank, I talked to the guy at my lfs... tried to get things planned out ahead of time (what I wanted to keep, and what I needed to keep them alive, etc.). I knew I wanted a reef, but I also wanted a trigger. My lfs said that nigers were (typically) the least likely to cause damage in a reef, but other triggers were sure to munch on corals and inverts. The trigger was the first fish I bought after the cycle, and I got him hooked on stricly flake food to start... no live or frozen fish. I've had him for about 8 months now, and very few problems. The only catch with him is that he is very curious, and rather intelligent. He is always checking things out, and carefully inspects all new additions to his environment. He will pick at fish that are significantly smaller than him (< 1/4 his size), and he likes to pick at things that stick off of fish... like antennae (like that thing on a fire goby). Thus far (knock on wood) he has not been a problem for me.
manis (part II) - I did a boatload of research on equipment, and everyone gave me a different opinion on things like filtration, lighting, etc. Seems like the only agreement is that when in doubt, go overboard. Common theory is that the more gear you have, the better. I decided that the best thing I could do was to pick on person to get advice from... that would elimiate confilicting info, and then to rely on my years of experience with freshwater fish (I know, they are very different, but the basic theory behind them is the same). My lfs has this theory, which I agree with - keep it simple! We had a discussion last week about this kind of thing, and basically decided that going with sumps and skimmers and coolers and all the other gear that's available is fine, but you are basically manufacturing a good environment (if you are lucky). Why spend all that time and energy and money trying to force the issue... why not take an extra couple of weeks at the start of things (and a few preventative measures here and there) to get a good, balanced ecosystem that will take care of itself? I have had things running for about a year now, and have had no problems (except for a breakout of ick). My water parameters are all very steady... nitrite-0 nitrate-<10ppm (holds steady at 5-10ppm no matter what) ammonia-0. The only thing I really keep an eye on is pH, which I have a hard time keeping above 8.0, and salinity which rises and falls as water evaporates and is replaced. I do a 25% water change about ever 6 months or so to clean out the sand and gunk in my undergravel filter. But the most important thing... DON'T OVERFEED!!! I feed a small pinch of flake food once a day, 6 days a week. On the 7th day I rest... hehe, just kidding... actually, I feed them frozen brine shrimp, and I feed my corals and anemones an invert supplement I bought at my lfs (not sure the brand off the top of my head). But who knows, maybe I have just been lucky... and real disaster is on its way.
Hope this helps... any ohter questions, feel free to ask.