View Full Version : Measuring PAR of LEDs

08/22/2014, 11:23 PM
I just borrowed my local club's Apogee Quantum PAR meter today. I plan to take measurements at different points in my tank with different light channel intensities of my Evergrow it2080 LED light. I have read that the meter doesn't read the PAR of LEDs correctly and need to be corrected for more accurate results. I came across this page (http://www.apogeeins...ng-diodes-leds/) that describes the error. If I read this correctly, would the meter value read ~15% lower than the actual PAR based on my layout given below? I figured that correcting for mostly the 12k and 450nm light would be sufficient since they represent around 75% of the light output.

12k White - 28
6500K White - 4
420 Purple - 6
450 Royal Blue - 46
480 Blue - 4
520 Green - 4
660 Red - 4
480 Moonlights - 3

Anyone with the similar light correct for the values given by the PAR meter?

Big E
08/23/2014, 05:01 AM
This article will help with some of your questions---


A few basic suggestions I have is that make sure you have it set on "sun" mode for best accuracy.

I wouldn't be so specific about splitting hairs even if it reads off 10%. In reference to the range we keep most corals a reading of +/- 50 isn't going to matter much to the corals.

It's the very highs & lows you have to concern yourself with the most.

In general Sps do best between 200-450........LPS-- 100-250.....Chalices like 100 or under

Zoz/palys about 250 or under