View Full Version : White LEDs
The ulta bright ones commonly used in flashlights have wavelenghts ranging from 420 -700 nm.The relationship between wavelenght and color temp in degrees Kelvin is : Wavelength (nanometers) = 3,000,000 / Col temp (Kelvin).
So at 4,500K, the peak wavelength is 666nm (red) at 6,000K the peak wavelength is 500nm (bluish green) and at 7,500K the peak wavelength is 400nm (deep blue)
The question is what color temp do corals do best at ?
Seems to me that the right wavelength LEDs would make excellent spotlights and accelerate coral growth while limiting algea growth if waterproofed and properly installed.
The only company I've seen successfully do this with LED is Solaris and cha ching...
http://www.jlaquatics.com/phpstore/store_pages/tlist/ledlighting/ledlighting.php?category_ID=144
Sploke
08-06-2007, 2:07 PM
Wow those are amazing lights.
I still think I'd stay with MHs. Even with the extra energy cost and heat I've become addicted to the shimmer.
Jeeze Louise! Talk about profit. I was thinking along theres lines or even just a didcreet LED here and there to spotlight your favorite specimens.
http://www.plantservices.com/vendors/products/2005/004.html
The LEDs arent all that expensive.
http://www.maplin.co.uk/searchtemplate.asp?criteria=HIGH%20OUTPUT%20LED
Amphiprion
08-07-2007, 9:53 AM
Corals will grow fastest at a wavelength that properly mimics natural sunlight. That being said, if you don't have the intensity, then even spectrum is useless. When it comes to LEDs, the bluish ones are actually brighter than white ones (though not visibly). While the LED fixtures have proven themselves to be bright enough for many corals, IMHO, they still haven't gotten far enough with the technology, yet. If you really wish to go with LEDs, then give it a few more years. Until then, maybe invest in metal halide lighting, t5 lighting, or a combination thereof.
Corals will grow fastest at a wavelength that properly mimics natural sunlight. That being said, if you don't have the intensity, then even spectrum is useless. When it comes to LEDs, the bluish ones are actually brighter than white ones (though not visibly). While the LED fixtures have proven themselves to be bright enough for many corals, IMHO, they still haven't gotten far enough with the technology, yet. If you really wish to go with LEDs, then give it a few more years. Until then, maybe invest in metal halide lighting, t5 lighting, or a combination thereof.
Hey bro, are you aware of the additive property ? If one LED produces X lumens the two will produce 2x lumens. And so on. You can make the light output any colur you want and as bright as you want too. BTW, Ive been involved in electronics for 30
years.
Looking at it another way- the photons dont care where they come froon just how much energy they have
Amphiprion
08-07-2007, 1:40 PM
Hey bro, are you aware of the additive property ? If one LED produces X lumens the two will produce 2x lumens. And so on. You can make the light output any colur you want and as bright as you want too. BTW, Ive been involved in electronics for 30
years.
Looking at it another way- the photons dont care where they come froon just how much energy they have
I am very aware of the additive property of light--I took several years of physics for my degree. I have been involved in the biological dynamics of light for 10 years. The additive property has nothing to do with anything I said, which is where I think you are misunderstanding. Also, your LED lumen analysis isn't necessarily accurate. If you were to measure the lumen output of a blue colored single LED, it will emit more lumens per unit of energy than a white one. This has already been established. Also, if you look at the analysis people have done on the PFO Solaris, you will see that the bluer, 200000K version is measurably brighter (in terms of PAR, the only useful light measurement in our circumstances, other than PUR). Why is that? It contains no more LEDs, no more wattage, etc. The opposite is true in other light sources. "Daylight" colored MH and fluorescents are measurably brighter than bluer ones (usually). We aren't concerned about lumens here, but PAR.
Well I've not had any of either your experience in electrical gadgets....I just think the MHs look "purty" =)
Amphiprion
08-07-2007, 7:31 PM
I like the look of MH the best, honestly, even though I use T5s. It just gets the job done with less space (vertical, that is). Of the LED tanks I've seen, I haven't liked the look. I hate flaunting experience, and I ended up lowering myself by doing it earlier. It is one thing to try to politely correct someone, but treating them like an idiot is something else altogether. Sorry if I came across as harsh (or pedantic) in my earlier post, zkt, but I interpreted your reply as a bit condescending.
I saw the LEDs in action as well and thought "well where is the shimmer?" Of course they won't have the obnoxious electrical bill each month but hey a girl likes sparkly things. :)
Amphiprion
08-07-2007, 7:40 PM
Yeah, it's hard to give up that shimmer.
Well alrite! Guess this forum isnt so dead afterall. Perhaps the difference in light quality spoken of is due to the wider spectrum of MH as compared to LED ? LEDs tend to output at a specific frequency and have a high Q factor, whereas MH have a broader, flatter curve on the frequency vs intensity graph which more closely matches sunlight, and hense, appears more natural to uor eye. However, it is well known that plants respond much more to blueish light than the other colors. I dont know if this is true of corals and other marine life. But if it is, then perhaps a LED light source could be tuned soas to optimize coral growth. My original idea was to use LEDs as spot lights anyway and not as the main light source.
QuagmireMan
08-08-2007, 1:37 PM
I have been putting together a LED spot light setup. I really am going to have no controls other than going through a varible resistor to change the brightness. I wanted to use mainly blue because I love the colors. I will try to get this together and let you know how my sponge and algee reacts.
Well alrite! Guess this forum isnt so dead afterall. Perhaps the difference in light quality spoken of is due to the wider spectrum of MH as compared to LED ? LEDs tend to output at a specific frequency and have a high Q factor, whereas MH have a broader, flatter curve on the frequency vs intensity graph which more closely matches sunlight, and hense, appears more natural to uor eye. However, it is well known that plants respond much more to blueish light than the other colors. I dont know if this is true of corals and other marine life. But if it is, then perhaps a LED light source could be tuned soas to optimize coral growth. My original idea was to use LEDs as spot lights anyway and not as the main light source.
It really depends on the what you'll be stocking your tank with. No one here has all the answers and not a single one of us does things exactly the same as the next person. With that said corals tend to do better in the white range of 10,000k bulbs versus the bluer 20,000k bulbs...many of us split the difference and go for 14,000K bulbs.
Coralline algae however does better in the blue range. Some corals aren't even photosynthetic and don't give a flip what color bulb you're using or if the light reaches the bottom of the tank like a good LED system, MH or T5 with individual reflectors will provide.
I'm not an electrician, don't pretend to be one so I'll not be trying to make my own LED system. For me personally, and with what I wish to stock in my tank I choose an intense light (2) 250 watt MHs that will allow me to put even high light demanding species at the bottom of the shallow 55g, and I have 10,000k bulbs to start the corals with plans to switch to a bluer 14,000K next time.
For you, you might not be stocking high light demanding species. You might just be keeping fish even and a basic flourscent will do...or you'll try a DIY LED. If you do go the DIY LED route however I'd urge you to not fully stock the tank with anything that is demanding until you're sure the light can support them.
Alrite bro ! Gald to hear it. I`d much rather build my own than buy some over-priced piece of junk. Following the KISS principle is a good idea. But can`t say I think much of using a pot alone to control brightness. How many LEDs are you going to use ? Calculated the values yet ?
I like the look of MH the best, honestly, even though I use T5s. It just gets the job done with less space (vertical, that is). Of the LED tanks I've seen, I haven't liked the look. I hate flaunting experience, and I ended up lowering myself by doing it earlier. It is one thing to try to politely correct someone, but treating them like an idiot is something else altogether. Sorry if I came across as harsh (or pedantic) in my earlier post, zkt, but I interpreted your reply as a bit condescending.
Well, you read it right- it was. LOL. But I`m willing to forgive, forget and move on.S ure you are too.
Thanks Grins- thats what I was wanting :) But 500 watts on 4 sq ft ? :eek3: Have you by any chance calculated the intensity/ sq ft or measured it? I have a 250 MH lamp lighting 6 sq ft of plant growing area and gotta be careful else the light will burn them up and from light intensity not heat as you might think. Course it all depends on how close the light is. Inverse square law ya know. 70 MH watts does 4 sq ft ok.I think I have developed a pretty good feel for light intensity in my gardening experience. Unless you have the light really jacket up to the ceiling seems like too much. But on the other hand you sure seems to know what youre talking about. Wheres the icon for confused ?
I'm good with plants as well...used to own a garden center in fact.
But on the SPS I'm keeping and the clams I wish to keep this lighting is good for the tank. Everything is acclimated to the light and I've seen similiar set-ups done. The bulbs are 13" off the water surface and even the zoas and LPS are doing well.
The only thing bad about 500watts over my tank is the electric bill. =)
I found the problem. The bulbs I use in the grow box are 400 W not 250. LOL
38,000 lumen MH conversion lamps. Agromax by brand name. So it all makes sense now. Except the reason why stuff is growing so well in my 10gal SW tank with only 2 24" florescent tubes 3" ablve the water(1900 lumens total). Not nearly as bright as a Florida summer but life continues to develop out of the rocks. Makes me wonder what else is in there and just waiting for the right conditions to start growing.
BYW, anyone wanting to experiment with the ultrabright LEDs had better have a LOT of them. Even the best ones put out about 0.5 lumens !
http://led.linear1.org/lumen.wiz
http://www.superbrightleds.com/leds.htm
The 1 watt type would be a better choice. Theyre may well be higher output units available now.
If anyone wants to build this sort of thing, especially the guy who`s planning on using a pot to ontrol brightness, lemme know and I will lend a hand.
Its on my todo list but not very close to the top.
QuagmireMan
08-09-2007, 11:11 AM
I was thinking of using these LEDs
http://cgi.ebay.com/New-Product-100X-10mm-JUMBO-White-LED-Lamp-140-000mcd_W0QQitemZ250151581767QQihZ015QQcategoryZ669 52QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
along with some 12000mcd 3mm blues i have
I really like the blue colors :-)
Cant believe those are really 140000mcd at ~20 ma. The 1 watt types dont put out that much. Check this out :
http://www.quickar.com/leds.php
But if its correct the light output is in the neighborhood of a 15 watt cf lamp. But a lot more focused. :) You`ll need 2-3 amps to run em. An old computer switching power supply is more than adequate. Keep us posted.
You guys might have more replies to this in the DIY forum. Some of the people that post there don't always venture in the Newbie forum.