So got in a par meter that hoppy had converted over from a lux meter. (Big thanks to hoppy there!)
According the information the numbers will be roughly 15% high however, the numbers are still suprising!!
ALL NUMBERS ARE OPEN AIR
On height above the meter I went from 0-36" and then out from the center 6" and 12" though the numbers may not be 100% accurate they are close enough to give this fixture some definite warrant!!
Height 0" / 6" / 12"
0" 450 / na / na
12" 220 / 140 / 6
18" 140 / 108 / 12
24" 108 / 100 / 28
30" 83 / 90 / 45
36" 70 / 75 / 49
The underlined ones I found odd, because the 6" out from center is higher then directly underneath, I think this is due to the fact that when I tested out from center I had the light against a wall, BUT this is probably still accurate due to light that gets reflected back from your glass. At any rate, this fixture is surprisingly strong!
You can also tell from the measurement of par from 24" and under the light has a very narrow beam pattern, but in a tank 18" wide or less you would still get significant coverage.
Once I get my new tank up and going, AKA finally getting the glass and assembling it I will do more readings and then some with water.
Here is a link to the unboxing of the fixture
Beamswork 36" with 3w led