LED question

[xavier]

Hi there;

Just one question concerning LED
If you want to keep same Watt/Gallon with LED as with T5, how can I get the LED qty I need?
Example; if I have a 100G Aquarium with T5 lights of 400W (1G = 4W) , how many LED do I have to use??

Thanks!

 

[UnknownWaters]

I would imagine you dont need equal watts if im not mistaken its the lumens that matter. Ask Wingo he can help you.

 

[Aqua Pro Builder]

According to Dept of Energy, the light output(efficience) of LED is 2.5-3 times of fluorescence light.

It also depends which type of LED you are getting:
SolarPod-5 LED emitter produces 3100 lumens at 50W (*no direct comparison of other wattage LED as SolorPod-5 is custom made to 20,000K-22,000K*)
Some 1W LED produces 80 lumens at same color
Some 3W LED produces 150 lumens at same color
Some 3W LED produces 100 lumens at same color

For blue light, LED is even more efficient relatively.

 

[xavier]

That's what I need!
Thanks!

 

[TOTAL AQUARIUMS]

watts per gallon is an old rule that no longer applies. There are other aspects of the light that are far more important.

 

[Marteen]

For LEDs you want coverage not wattage. Remember that a 3w LED produces the same amount of light throughout it's cone of illumination but that area is not wide and depending on what kind of optics you use can be quite narrow. The rule of thumb for spacing LEDs is you want at least 2" between 3w LEDs with row spacing between 1-1/2" to 2". This will give you a good amount of coverage, also remember that 1w LEDs do not produce enough penetrating light to be useful in our aquariums.

So for example if you had a 20" L x 15" W display area 24 to 32 LEDs would be a good amount of coverage. You would want a heatsink that takes up close to the entire length and at least half of the width you are trying to cover. Once centered this type of fixture will provide a good amount of light coverage and allow for some low light spots along the front and back of the tank. Remember that the more LEDs you can fit on your heatsink, not crammed in but spaced evenly, the better. You can always adjust the brightness levels if needed with a pot.

 

[xavier]

Thanks Marteen !

 

[cali_reef]

Lumens are not the correct measurement for how much light Coral can use, PAR is closer.

Here is another emerging technology that will "light" the reef scene soon..

http://www.youtube.com/watch?v=lTGsM9pplUs

 

[Aqua Pro Builder]

Even though better to have PAR values, you don't have to worry too much about difference between lumens and PAR for LEDs as long as the LEDs you are buying are not green nor out of the ordinary photosynthetic spectrum such as UV ...

Even PAR is not very accurate for coral growth as some coral reacts differently to different color of light

 

[xavier]

then Wingo, is there an indicative "rule" we can follow in order to select the LED for our systems?
Thanks

 

[Aqua Pro Builder]

For good look, 455nm to 465 nm blue LED is good and you can use the lumens ratio. 1 watt LED(the latest kind) for every 2.5/3W blue actinics fluoresense.

For growth, no idea what guideline you can use as reefers cannot agreed on what wavelenth corals grow best on. Furthemore, few manufacturer of LEDs(mh manufacturers too) released their PAR values. In fact, most PAR values or other aquarium lights are done by individual expert like Sanjay or other hobbyists. Therefore, there will be no reliable way to say how watt of LED for how watt of fluorescence/mh can be drawn.