i have noticed that mine likes moderate flow. if i put it in too much flow then it starts dying off and if i put it where it doesnt get much flow then it starts dying. mine seems to be sort of tempermental . just a thought....
180g tank (3) 175 mh (4) t5ho (3) hydor 4 proclear 200 pro wet/dry with skimmer
calcium: 440
phosphate 0
nitrate 0
ph 8.3
salinity 1.024
alkalinity 9
placed in middle of tank pretty good light moderate water flow
Mines about 7" from a 150 watt metal halide, with a powerhead pointed at it, and its flourishing. I think something might be eating it, or it just doesnt like its spot
Edit: Your lights are kickin pretty good, maybe just move it a little. The 0.002 wont make any difference.