[Canadian]

Steve,

I don't think you can reasonably compare readings from person to person (i.e. your measurements to his). The lack of control for calibration and differences in measurement techniques makes for an unreliable comparison.

I read that same (re: the 400W with LumenBright reflector) thread Steve. I actually thought I had posted it in my previous post but I guess I forgot to. Anyway, that 400W MH setup produces considerable PAR. In fact, to the point of photoinhibition. But I don't think you can compare a crappy passively cooled Tek fixture with Workhorse ballasts to 400w 12K Reeflux bulbs with LumenBright Reflectors and a Coralvue ballast. Part of me wishes ReefGeek wasn't so slow to get the PowerModul in when I requested it. Then we would have a high quality T5 fixture to compare things to.

Additionally, it has been well documented that, for instance, magnetic HQI ballasts draw significantly more wattage than the stated/rated value. So when people are tossing about comparisons regarding "efficiency" I sure hope they're actually measuring the true wattage drawn and not assuming that because they're running a 250W MH that it's pulling 250W.

Ultimately I find the T5 vs MH comparisons tiresome. They both work - it has been well documented and there are plenty of pretty pictures to support the use of both. Pick the attributes that most appeal to the user and go with it. Alternatively take advantage of the strengths and weaknesses of each and combine them.