My thoughts aren't directly pertinent to the triton method but I thought I'd share them in case they somehow were tied to the issues you've been having. Since I set my tank up a year and a half back, I always maintained it as a ULNS. All my corals would go through the same downward spiral that you describe - colored up the day I added them to the tank, and over time gradually lost all color.
Over the past coupe of months, I have been keeping an eye on my nutrient levels, especially NO3, and maintaining it between 2-3ppm. PO4 is usually trace. Since I started this, my tank has done a complete 180. Colors are coming back in, and new corals that I have added have not any of their color. I am also seeing increased PE and noticeable growth as well.
Now ... this might just all be nothing more than a coincidence, but I like to think the nutrients played a part in the turnaround. I am not sure if the triton method by design is meant to be run as a ULNS or not. If it is, you can ignore everything I said
One other thing to watch for is your Alk level. I know that higher Alk levels, combined with ULNS can often lead to burnt tips on corals. It is suggested that Alk be maintained between 7-8 in a ULNS.
What puzzles me is the loss of fish as well. That certainly points to something in the water that is not right.
Just my two cents...
