Reef Brite LED's available in Canada

[Ron99]

Looks nice. Can you do some PAR measurements?

Also, just for the sake of clarity when comparing LED units, The Reef Brite strips power their LEDs at something like 1.5W or 2W each.

[PFoster]

Originally Posted by Ron99

Looks nice. Can you do some PAR measurements?

Also, just for the sake of clarity when comparing LED units, The Reef Brite strips power their LEDs at something like 1.5W or 2W each.

Sorry but we dont have a PAR meter right now. I do have a lumen meter that I use to compare the difference between reflectors when using the smae lamps and the same ballasts but that wont help us here really.

[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.

[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.

[Ron99]

Just as a follow on, I'm not trying to poop on the product or anything of that nature. I just feel that with LED technology being fairly new to our hobby there is alot of misinformation, misunderstanding and marketing hype such that people don't really know exactly what they are getting and what the particular LED fixture they are buying is capable of doing. The manfacturers don't help in this as they don't release important specifications on their products and they don't publish PAR numbers (which they must have tested).

So what happens is a customer buys an LED unit to replace MH or T5HO or whatever and then it doesn't have the results or performance they believed it would so they conclude LEDs are no good and get on the interwebs and talk about how bad LEDs are and how their corals stopped growing or lost colour etc.

I believe LEDs are the future of reef aquarium lighting and can replace T5HO and MH in most applications if implemented appropriately. That means high quality LEDs driven at 3W with secondary optics if you need very high PAR or want to have penetration in deeper tanks. Bare LEDs without secondary optics for lower light requirements or shallower tanks etc.

I believe Reef Brite's literature says these can replace T5 and VHO lighting which probably means (if you read between the lines) that these will not perform as well as MH or T5HO. So they will be great for some applications but not for very high light requirements or penetration into deeper tanks.

[Jaws]

So what depth are you suggesting they would be good for?

[Ron99]

Originally Posted by Jaws

So what depth are you suggesting they would be good for?

Not sure if this question was directed at me? If so, the answer is I have no idea. I don't know the specs of the specific LEDs they are using nor the actual drive current (but from the power consumption of the strips I am guessing about 500mA). The only way to really know is to measure PAR in a tank at different depths. These look plenty bright on a small aquarium using 4 strips for a total of 24 LEDs at $600+ and may work great for the Cardiff application. On a bigger, deeper tank? I don't know.

[PFoster]

Picture links are all now fixed on page 2. Sorry about that.