[danny zubot]

Well, first off I don't have a meter to say what my par is. My tank isn't the same size as yours so my issues could be completely different. I'm running a 400 watt XM 20K in a 22" squared luminarc reflector over my cube, which is 24x24x22". Some corals that are dead center, and 10" below the water surface are colorful and thriving. While others at the same hight and off to the side are brown but still have polyp extension.

What I've been thinking for the past while is that the reflector may have hot spots which may be burning some of the corals. Thus I have the light quite high over the tank, like 14-16" above the water. Now I'm second guessing my theory, and wondering if these "unhealthy" corals aren't getting enough light. By using your readings with a similar bulb and reflector as a base-line, how much higher do you think the par would be if you had a 400 watt bulb instead of the 250?

In your opinion and based on the readings you posted on this thread, what is the optimum par reading for the corals you have. It might give me a better idea of where I stand with mine.

Thanks,

Danny