My Maxspect R420R (RAZOR) PAR readings

[Clark]

Here's the PAR readings for my Maxspect R420R (RAZOR) 120W 16000k fixture.

http://www.maxspect.com/index.php?option=com_content&view=article&id=20&Itemid=21&lang=en

I'm using the stand that came with the fixture which places it about 6" above the water line. My tank is 36x19d and my top line of corals is at 7" depth below the surface. My sandbed corals are about 14" below the surface so that is where I've taken readings. I took readings in columns down the center of the tank, 7" to the right of center, and 14" to the right of center. The RAZOR has a "white" channel and a "blue" channel so you'll see two settings in each block. I ran both channels at the same setting. The measurements were taken with George's Apogee sensor. (Thank's George!)

PAR can change a lot with just a small re-positioning of the sensor so don't expect perfectly proportional changes between my samples.

PAR at 100% white/100% blue:

Depth Center +7" +14"

7" 720 400 10

14" 400 300 90

PAR at 75% white/75% blue:

Depth Center +7" +14"

7" 500 300 10

14" 250 150 80

PAR at 50% white/50% blue:

Depth Center +7" +14"

7" 130 60 10

14" 80 50 24

I hope this info helps those shopping for LED lighting.

[Clark]

Here's a pic showing illumination at 75/75

[Planeden]

Strange. My results with my AI sol was linear with power. So at 50% power the PAR was 1/2 of the full bright.

Did you do a blue correction for LEDs? Blue values tend to be under reported by 20-25%. But this may vary by measuring instrument.

[Clark]

I followed the instructions given by the fellow at RCA. He said to multiply the mV reading by 6 because these are LEDs. He said MH users would multiply by 5.

Could be that 50% on the maxspect dial is not the same as 50% on the AI sols. The internal electronics can do anything they want based on a dial setting.

Clark

[Planeden]

Yes, I suppose they can make the numbers mean anything they want. Seems confusing, though. If you wanted a PAR of 200 in the center, you'd have to test a bunch of different levels to dial it in.

[Clark]

That's why I borrowed the meter.