Reef Brite LED's available in Canada

[Ron99]

Originally Posted by PFoster

The Reef Brite LED strips actually use 3 W LED's that are being under driven so as to decrease the heat the generate and therefor increasing their live expectancy and depenadbility.

Yes, for marketing purposes they all say they use 3W LEDs. That means the LEDs are rated up to that power but are often actually driven at lower power to reduce heat and increase longevity as you state. But the actual output and therefore PAR will differ at different drive currents. Two different brands could use the exact same 3W LEDs but give different performance because they are driving at different currents Most manufacturers usually don't say exactly what current they are driving the LEDs at. FWIW, I believe that the Reef Brite uses Edison Opto emitters that are built using Cree chips so they are decent LEDs but the output is decreased from the max potential because of the lower drive current.

So as an example let's look at a Cree XR-E 3W cool white LED Q5 bin:

@350mA drive current the LED is using about 1W of power and generating about 107 lumens

@500mA drive current the LED is using about 1.6W of power and generating about 145 lumens or 1.35 times the output at 350mA

@700mA drive current the LED is using a bit over 2W of power and generating about 177 lumens or about 1.7 times the output at 350mA

@1000mA drive current the LED is using about 3W of power and generating about 235 lumens or about 2.2 times the output at 350mA.

PAR will probably correlate well with the lumen output so you have roughly twice as much PAR running at 1000mA vs. 350mA. Or to put it another way, you can probably light a tank twice as deep with LEDs running at 1000mA vs. LEDs running at 350mA.