# Planted Aquariums and High Power LEDs.



## Indignation (Mar 9, 2008)

I don't think anyone doubts the PAR of high power LEDs. I think the main barriers are price, and a pretty intensive DIY process. for someone who doesn't understand current/voltage or soldering, it is a lot to learn. I've followed several LED builds, and there is a ton of knowledge involved in doing it well.
I think one big reason that LED hasn't caught on as big here as with the reef crowd is color spectrum. While royal blue + white LEDs look awesome on coral, there isn't a good reproduction of red/yellow/white light that brings out the most color in plants. From what i've seen so far, LED planted tanks look a little washed out. Once someone finds a combo of LEDs that look as nice as a good set of giesemann bulbs do, I'll jump on board.


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## lauraleellbp (Feb 3, 2008)

I think Indignation nailed it.

I won't touch LEDs personally till they come up with good fixtures for planted tanks (I don't DIY electrical stuff) that can compete in price with T5HOs.


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## Green Leaf Aquariums (Feb 26, 2007)

You answered this in your post They are simply not cost affective, yet.
Next year you will see LED in every house as the new standard in lighting. Kinda like when CFL came into the "light".

There are LED fixtures that are very suitable for planted tanks in every way. Many folks in Asia and Europe now use them with unbelievable results. Italians have a whole line of planted tank LED fixtures that would make most plant geeks drool.


-O


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## garuf (May 30, 2007)

I don't know, I've priced it up and I can build a high power LED Luminaire, equal or greater in power to a 150w halide for £90, the cheapest I can buy a halide is £160. Then there's running costs...
Arcadia recently discontinued it's cheaper luminiare range and the replacements start at £300 and have 4 too many tubes for most people!

I personally think they're cheap enough and powerful enough, I just can't understand why manufactorers aren't stepping up and producing the goods.

I'll be building my one as I have the time available. The biggest issue is the light spread being limited but I'm sure this can be resolved.


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## Walking_Target (Jul 16, 2008)

I can understand some people being turned off by the DIY angle, not everyone has the know-how to do it. 

The thing that gets me is that people think that an LED setup for plants is MORE expensive than T5HO. Assuming you DIY an LED fixture than buy an overpriced K2 or something similar, LEDs are cheaper within two years. 

Let's go with a 20g tank. To light that, you need around 8-10 LEDs in a staggered strip, you can get away with less, but the spotlight effect will be even more pronounced.

for argument's sake, let's go with an even dozen. 

that's $70 and change plus shipping through most LED sites. Add a Meanwell ELN-60-48D and it's another $40. so $110

The cost of all the wiring, jacks, project box and another power source to make a 10v PWM circut to control the dimming, it's another $30-40. 

So we're up to $150 USD not including shipping. If you live in the US shipping is a negligable expense. 

Last but not least, you need a heatsink/mounting solution. Any old or non-fuctioning fixture is perfect, then you grab either a bunch of old computer heatsinks or you go to heatsink USA and get what you need. another $~30-40, maybe less, maybe a touch more. Depends on what you already have and what you can get. 

So at the outside, you're looking at around $200 plus your time to make everything. The instructions on how to assemble it all are easily found on the net (I mean, I can do it...) A good T5HO fixture costs a mimimum of $150, plus the recurring expense of the bulbs every year, usually $30+ a piece. Colour rendition is a concern, but most fixtures use cold white LEDs (10k color temp) this could be switched up with a couple warm white LEDs to bring back the red/pink spectrum. 




FYI- the reason that LED fixtures aren't more common yet is because a company called Orbital Techonlogies (orbitech) that does primarily aerospace research on the US gov'ts dime, holds a patent on LED aquarium lighting and has sued PFO out of existence over it already. The patent itself is questionable at best, but they just tie up smaller companies in legal proceedings until they run out of cash.


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## F22 (Sep 21, 2008)

Check out marineland hi-lites. They look really good and as soon as they become available from my wholesale acct I will demo and review.


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## Walking_Target (Jul 16, 2008)

Can't seem to find them on the web. If they're anything similar to the Stunner Strips put out by Ecoxotic, i'm not holding my breath.


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## F22 (Sep 21, 2008)

Noooooo, these look really good and my shop will be retailing them at $169 for the 24-36" strip.


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## F22 (Sep 21, 2008)

Error, they are called double brite leds. I'm an idiot.


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## GTR (May 27, 2009)

http://reefbuilders.com/2009/09/25/double-brite-leds-marineland-thin-stylish/


http://www.3reef.com/forums/reef-lighting/marineland-double-bright-led-lamps-hi-res-look-74623.html


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## Walking_Target (Jul 16, 2008)

Definitely not holding my breath on those fixtures either - what I've heard from our marineland dealer is that they're going to be stupidly expensive, way above what comparable T5HO or DIY LED will be, not to mention they are not suitable for plants.


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## JDowns (Mar 6, 2008)

When looking at LED fixtures there is a monumental difference between high power led's as from Cree and high bright led's. I would be extremely wary of any high bright led's currently on the market (the led replacement tubes come to mind). Most high bright led's after testing loose an extreme amount of PAR after just 200 hours. You cannot under cool and over drive a high bright led and expect it to last, and the same can be said for HOT5, and high power led's. Most high bright led's whether 3mm or 5mm are junk for the money and I would bet you won't get a years worth of use out of them due to inadequate heatsinking and under-cooling. Candlepower forums has some really good information and studies for those really interersted in diy led's. For now the high power led's on the market are grossly overpriced in comparision to T5's. I can measure Par from a $300 LED pendant and compare to a $30 dollar 3D led Maglite and the Maglite blows the pendant out of the water. The biggest cost I can see that needs to come down to make led's more economical is going to be in the optics, and that will come with volume.

I have to disagree with having to replace bulbs every year. If you actively cool your fixture and bulbs you can get much longer than a year out of them. I have two year old Geisemann's that have only lost 5% compared to new bulbs.


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## crossbow (Nov 29, 2009)

I think the other problem is that LED lighting is already obsolete. We've now got Plasma lighting and OLED lighting on the horizon. By the time we get LED lighting all sorted and affordable, there will be better solutions on the market place.

http://news.cnet.com/8301-11128_3-10194915-54.html


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## F22 (Sep 21, 2008)

Such a bummer. May not be worth it.


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## JDowns (Mar 6, 2008)

OLED's are definatly a step up, and will only make led's more affordable. If you track the cost per die over the last five years you can see the steady decline in cost in comparion to improved luminosity per watt, which makes cooling more efficient in reduced mA usage.

I doubt plasma's will ever make it into the home. OLED IMO will win that battle. As OLED gains the market share it will push plasma out of competition, which one can already see happening in televisions. Consumer electronics will dictate this winner of this battle. Lower production cost, smaller units due to scope of each technology, smaller units = decreased cost in packaging and shipping, etc. OLED has the advantage.


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## Walking_Target (Jul 16, 2008)

OLEDs won't make it big for aquarium lighting, at least not for the forseeable future. The main use of that technology is for displays. It'll be neat to see it come out as a lighting source, as they are capable of doing, but I highly doubt that they'll be available for aquarium use for at least another 5 years, and DIY seems unlikely, which means the cost will be high for quite a while. I'm very interested to see the flexible displays that they can apparently make with OLED tech though. 

Plamsa lights, while promising, would suffer from one of the same probelms that plagues metal halides - they're a point-source that requires a fairly large fixture. That's to say nothing of the microwave/RF frequency radiation that those fixtures pump out to excite the plasma; pumping out enough radio/microwave frequency radiation to cause plasma incandescence is worrying to me from a scientific/health perspective. I'm with JDowns. I doubt plasma lighting will ever make it into home use, never mind aquarium use. 


The benefit to current LED tech is the high efficiency per watt. at full usage, you get an efficiency of about 61lm/watt, if you're not driving all sorts of current through the element, you'll see efficiency rise to about 80-100lm/watt. for most applications, with a large enough heat sink, passive cooling is more than sufficient too


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## JDowns (Mar 6, 2008)

I agree led's as an affordable light source are still years out. Oled's will make current led's second stock and very affordable for DIY or special applications for a small window of time. But given the longevity of use the investment in a fixture may be worth it. If current trends hold then organic led's will be the defacto in light source whether it be in displays or space illumination. Pholed's are looking to be the future for replacing incandescent lighting. Universal Display Corp has some interesting reading on organic led's and their future applications. I also agree that the Rf factor with plasma's is just another nail in that technologies coffin. The next 5 - 10 years will be exciting to see new technologies roll in. Organic led's, nano technologies, improved broadband spectrum, 3D displays, etc. Only thing that will delay some of these things are the entrenched special interest groups and funding.


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## JDowns (Mar 6, 2008)

Here is a photo from the last led/oled lighting technology expo. Tube lamp replacements will be a large driving force in this technology for office use. As the lumen to watt ratio improves the technology will become more used, and thus more affordable. I think the current results are around 100 lumens per watt. Only problem is the 50% retention in luminosity over the life of the fixture. The DOE according to Universal is pushing for a 70% standard. I also don't think it will be to long before companies in this country start sprouting up leasing bulbs to large office buildings like what is happening overseas.

I would think for our application or any horticultural use would be an over abundance of light from the start with dimming ability. Start the lifespan with a decrease in voltage and increase as the fixture ages, making the long term investment more feasible. Rather than an under abundance overpowered from the start limiting the lifespan, which current fixtures for the hobby have a large tendency to do.


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## NJAquaBarren (Sep 16, 2009)

When are you going to start carrying those Italian fixtures Orlando???


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## GTR (May 27, 2009)

I'm not up on any of this at all. At what point does LED need the cooling I keep hearing about. That Marineland fixture doesn't have many LED's compared to some other things I've seen.
I have a couple blue LED sticks I've used on tanks in the past for moonlight and they just use a regular DC transformer anywhere from 6-12v. They've worked for at least 5 years.

SteveU


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## Wasserpest (Jun 12, 2003)

Walking_Target said:


> So at the outside, you're looking at around $200 plus your time to make everything. The instructions on how to assemble it all are easily found on the net (I mean, I can do it...) A good T5HO fixture costs a mimimum of $150, plus the recurring expense of the bulbs every year, usually $30+ a piece. Colour rendition is a concern, but most fixtures use cold white LEDs (10k color temp) this could be switched up with a couple warm white LEDs to bring back the red/pink spectrum.


I can easily build a nice two bulb T5HO fixture for less than $75. The light output and color rendering will blow your $200 LED fixture out of the water, so to speak.

$18 ballast
$4 endcaps
$22 Miro reflector (4ft cut in half) 
$30 bulbs

With readily available Advance or Sylvania ballasts I can over- or underdrive this setup to fit it the type of tank I want. And no soldering involved.

You can get decent bulbs for ~$15, and they do not need to be replaced yearly.

The savings in energy are not that noticeable, until you get into reefer wattage range. (Assuming similar light output of the fixtures).

I use LEDs in many places throughout my house. And unfortunately, the advertised lifespan (some claim 100000 hours - I wonder how they tested that???) is often surprisingly short.

As efficiencies and quality go up and the price comes down, no doubt they will replace fluorescent lights. Give it a few more years.


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## JDowns (Mar 6, 2008)

One thing I would look for in any led product is warranty.

If we take for example Cree's data for an MC-E. With a current of 700mA and a temperature <= 135°C a rated lifespan of 50,000 hrs and retain 70% luminosity. With a 10hr photo-period and my rough math skills that's nearly 12 years of use. Let's not even account for return since initial investment_(currently)_ to energy savings is so far out there that most would not even still be in the hobby.

So with that data I wouldn't even consider a product if they would not warranty at least 90% luminosity in one year. Since any company can come and go, led lighting is ripe for consumer fraud. And it wouldn't be unreasonable to ask for 90%. Since any led product that can't retain that standard in 1/12 the rated lifespan is already doomed for failure. Given how fast Led's can fail due to being over-driven, designed with poor thermal management (ala XBox 360), and/or poor current driver implementation, you would probably know something is up much quicker than 1 year.


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## MoonFish (Feb 12, 2006)

I've had crees on order for over a month. Project halt.


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## Walking_Target (Jul 16, 2008)

I ordered my crees a week ago, they've already shipped


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## crossbow (Nov 29, 2009)

> OLEDs won't make it big for aquarium lighting, at least not for the forseeable future.


OLED's were first used to push display technology, but they are showing up in lighting applications. CES had quite a number of OLED lighting companies present. The fact you can basically slap a sticker thin light on something, that outputs light equivalent to half a dozen or more high power LED's, is pretty amazing to me!


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## Walking_Target (Jul 16, 2008)

Yeah... about that... 

Sticker thin? sure. 

equivalent ouput to half a dozen Cree XR-Es in the same size as a bumper sticker? I doubt it. That's over 1300lm (very darn bright!) and with the current problem with retained luminosity, we're not going to see them as a light source for awhile yet. 


Oh, and if we want to talk about the cree MC-E, it's not even in the same ballpark.


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## JDowns (Mar 6, 2008)

Personally I would prefer the MC-E over the XR-E. If I'm not mistaken you get a higher lm to watt ratio with the MC-E, but the XR-E can be driven at higher mA. You can use Cree's product character tool to do easy comparison between products and evaluate your use. Another reason I would prefer the MC-E. At 700mA a proper array with optics should be more than enough light. Plus you can have much more control over color temperature with the a four die layout. Two whites, a red, and a blue all on three seperate channels dimmable would be the ultimate layout IMO. Depending on the cool whites coloration you may not even need a seperate blue channel, so three cool whites on one channel and a red. But much more versatile than a single colored die. Optics still IMO will make or break any design. Does you no good to have either too much focus in a tight spot or too much spill. And overlaping can cause hot spots. 

For drivers Cutter has some neat programmable drivers that may be useful to look over. Plus they have some multiple array (up) designs with housings that are cheaper than some of the pricey pendants in the hobby and as far as performance they are in a different galaxy.


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## guerdonian (Jan 14, 2010)

Ok, new guy to the forum, but been reading it for several weeks now, and this thread seems to have a good knowledge base to post my question. I have purchased a fluval edge 6 (forum linklantedtank.net/forums/planted-nano-tanks/95967-official-edge-thread) and many of us who have done so are having issues with additional lighting due to the tanks compact design. I would say the majority of us have already upgrade the stock Halogen lights to high output LED’s. The new replacement LED’s have a total wattage of 6 but have a total Lumens of 320. (Halogens were combined for 20 watts, don’t know the lumens) I would also say a good number of us are trying to upgrade the lighting in the most compact way possible, thus all the DIY jobs with LED’s. I still have a hunch that I require more lighting, and due to the space constraints, here are a few of the solutions I personally have come up with involving LED’s:

The Mississippi waterproof LED light strip, from ledwaves(.com) for a gain of 330 lumen
(insert the www and html because i am a newb)ledwaves.com/Mississippi-Waterproof-LED-Signage-Light-38-inches-p-19539 
Or a pair of taam rio mini sun fixtures placed internally to the hood
riopump.net/new_products_folder/MiniSun 
Or rigging up another set of the same LED’s I replaced the halogens with.

So here are my questions and if there is another thread that answers any of these a link would be much appreciated:

Is the age old rule of 3 to 5 watts per gallon no longer apply when you’re dealing with LED’s (keep in mind that half of the brain jargon mentioned in this thread I don’t quite follow)? is there a Lumen per gallon rule? How much Lumen is too much Lumen? Do I require a florescent for a bigger spread in the light spectrum?
When rigging up for my fluval 6, will any of my above mentioned suggestions work?


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## JDowns (Mar 6, 2008)

Lumens are a useless tool for plants. You can't rely on manufacturer rated lumens, its almost as bad as wpg.

Judging by those photos they are utilizing a spot. I would look into a wider optics that can diffuse the light somewhat. That way you spread the light out and avoid hot-spotting. For that depth you don't need a great deal of lumens from an led. You could probably even get away with some high brite led applications.

Something like this may even work. I have a box of these laying around and can measure their par levels. You will have to modify for mounting but that should be easy enough. There are probably a myriad of different options. Just going to take some searching and playing around. I personally haven't seen the insides of an Edge and can't tell from those photo's too well on how things might work or not.


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## Walking_Target (Jul 16, 2008)

Your best friend would be a Luxeon Endor Rebel Star with the 3 LED array on the star. Personal preference for a planted tank would be a mix of cool white and warm white, probably a 2-1 cool white to warm white, as the stated color temp of the cool whites is 6500k.


Keep in mind that one Cree XR-E Q5 is comparable to a 35w Halogen bulb.


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## talontsiawd (Oct 19, 2008)

I think the main reason it hasn't caught on is mearly the DIY factor and price. They are pricey for a DIY project. It isn't a hard DIY interms of needing extensive knowledge on electronics but if you are doing something bigger than a nano tank, it is a bunch of work, and a bunch of wiring. A diy t5 fixture can be done for way less, and it is very simple to wire up. I haven't done either on an aquarium but I have done alot with LED's and wired up some shop lights. The shop lights only take half a day, including going out and buying everything, grabbing your tools, assembling, and hanging. A LED project would be much more extensive.

I think another thing is it is more or less an experiment. I feel like I would have to invest in a PAR meter as well. I can pretty much just guess if a fixture will work on a tank if it is any other type of light because they are commonly used. On an LED fixture, I would have to start by going off of what little info there already is, then adjusting things to fit me.

I am intrigued by this but until it is common place, I just doubt I will actually jump on it, DIY or store bought. I already have something that is tried and true. The people who are very into this stuff will have to pioneer it because a lot of us don't want to deal with the unknowns.


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## F22 (Sep 21, 2008)

I got the marineland double brite led fixture friday, looks good. Nice hqi type shimmer, not enough light though. More info to follow.


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## lovingHDTV (Oct 15, 2008)

The advantage I see with LEDs is the ability to control the amount of light like a spot light. If I want a single plant to turn red and that requires a lot more light than I want to provide for the entire tank, I can put a LED "spotlight" on that one plant and get a very nice red color out of it. I can do this while keeping the rest of the tank at a lower overall light level, controlling the growth of all the other plants in the tank.

I'm hoping to find a product that will allow me to add these LED "spotlights" in a simple cost effective way. As for now, I just don't grow high light plants because I don't want my entire tank growing like crazy.

Maybe one day . . .

dave


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## redfishsc (Aug 29, 2010)

I have a 26 Cree LED setup from my reef. I'm using half of it over my 10g right now (too much light, got a lot of algae!..... ancistrus cats are quite happy). 


I find that a 50/50 mix of cool white and royal blue look good, although I think neutral white (~4200K) and royal blue would look better. 


But here's the trick, I'm using two dimmable drivers (Meanwell ELN60-48D) and my whites/blues can be independently dimmed. Thus I get a LOT of freedom in my color temp. 

I prefer a lot of blue, like a strong 10,000K look, esp. for the effect it has on cardinal tetras and other blue-colored fish.


Eventually I'm going to set up a 70g 'tall' that I picked up recently and use this whole array over, should be a good medium-light tank.


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## Green Leaf Aquariums (Feb 26, 2007)

EcoExotic is coming out with a new "Planted Tank" LED system in a few weeks. Check out there demo video..
http://www.aquaticplantenthusiasts.com/videos/3320-new-ecoxotic-led-aquarium-light-teaser-mov.html


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## NJAquaBarren (Sep 16, 2009)

Look forward to seeing them. Hopefully more reasonably priced than their other fixtures.


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## NJAquaBarren (Sep 16, 2009)

Any news on these Orlando?


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## Cottagewitch (Oct 22, 2009)

http://www.ecoxotic.com/ecopico-aquarium.html


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## NJAquaBarren (Sep 16, 2009)

Thanks CW, I've seen that tank, but I thought orlando was talking about a new light fixture only.


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## Cottagewitch (Oct 22, 2009)

NJAquaBarren said:


> Thanks CW, I've seen that tank, but I thought orlando was talking about a new light fixture only.


He probably was. I was thinking I seen some bulbs from that company recently and went to search it out and came across that tank and thought it was neat.


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## Hoppy (Dec 24, 2005)

Speaking of new LED light fixtures, I am looking at changing my 45 gallon tank into a low light, non-CO2 tank, so I have just spent 3 days trying to design a minimum cost LED light for it. Now you can get some relatively cheap LED power supplies, supplying constant current, at a voltage high enough to drive a series string of at least 8 LEDs, and at least 3 parallel strings of 8 LEDs. That drops the price a lot. Then DealExtreme now sells the Cree XR-E Q2 LEDs for less than $3 apiece. Finally, another member here posted a DIY LED fixture with the heat sink being narrow aluminum channels. Putting those three together I was able to drop the cost of the fixture to about $160, still high, but now competitive with T5HO. My fixture would be 36 inches long, about 14 inches wide, and with 24 LEDs, driven at 625 mA per LED, and should give me about 40 micromols of PAR at the substrate. If I go ahead with this, I will post a DIY thread on building it.


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## Cottagewitch (Oct 22, 2009)

Looking forward to that Hoppy! I'm seriously thinking my next tank will be another picotope with the light retrofitted with LEDs. So any DIY's I read will be most helpful!


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## NJAquaBarren (Sep 16, 2009)

How do you think your design will compare to the marineland double bright fixture Hoppy? We are very happy with ours at under $100 especially.

Wish I had a PAR meter.


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## Hoppy (Dec 24, 2005)

NJAquaBarren said:


> How do you think your design will compare to the marineland double bright fixture Hoppy? We are very happy with ours at under $100 especially.
> 
> Wish I had a PAR meter.


I'm just conceited enough to think that mine will be much better. :biggrin:

Seriously, there isn't enough data on that Marineland light to even evaluate it.


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## !shadow! (Jan 25, 2010)

I've ordered a 8k spectrum panorama led module for my 48g, its pretty much for a planted tank set-up. lt's on it's way to my home soon and well let's just say if l like it i'll be ordering a bit more maybe like 3-4 and spread them evenly suspended above my tank. l'll be posting pics of the look once they come in. l have to agree with some of the previous posts about the leds looking like geissman lightning. That's when i'll be dishing out my hard earned money but till then l like to experiment with led's and the look on my tank. Curiosity sometimes gets the better half of me and my wallet


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## redfishsc (Aug 29, 2010)

Hoppy said:


> I'm just conceited enough to think that mine will be much better. :biggrin:
> 
> Seriously, there isn't enough data on that Marineland light to even evaluate it.


If you are using XRE's and driving them at 500-1000mA, then your opinion isn't conceited  It's reality. It'll beat the socks off that Marineland light. 


By the way, have you seen www.satistronics.com? Their stuff IS coming in from China but I just received one of the their 10 watt whites. For our purposes, it would be a very cool light. Two over a 10g should easily be a "medium" light setup (at 5-7" over the water surface). 

Check out this thread:

http://www.carolinafishtalk.com/forum/diy-section/23095-diy-led-done-cheaper.html


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## Zareth (Dec 13, 2010)

this guy made a 500 LED flashlight wich comes to 50 watts, they arent high power leds either. I'd be interested in someone making a large printed circuit board that LEDs could easily be inserted into..

The thing about LED is you can make the exact light you want in theory.. 
Imagine 500 red LEDS, 500 blue LEDS, 500 green LEDS. That will create white light, and say you want more of the light in the red and blue spectrum you can just try 300 green 600 red 600 blue. It would be the dream light fixture but as the OP said this would either be $700+ fixture from a company or a $50-$200 DIY project requiring much patience and skill as well as the knowledge of converting AC power currents into DC currents and running LEDs in series and in parallel.

When I graduate college I will gladly build one, it would be worth it.


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## Zareth (Dec 13, 2010)

redfishsc said:


> If you are using XRE's and driving them at 500-1000mA, then your opinion isn't conceited  It's reality. It'll beat the socks off that Marineland light.
> 
> 
> By the way, have you seen www.satistronics.com? Their stuff IS coming in from China but I just received one of the their 10 watt whites. For our purposes, it would be a very cool light. Two over a 10g should easily be a "medium" light setup (at 5-7" over the water surface).
> ...


This is a misconception on your part. A 10 watt LED is going to be very inefficient. 10 watts simply means that it wants to be run at 10 watts, so you can figure out what resistors you need to use and what amps its going to pull. Compare the luminous flux of a 10 watt LED to a 1 watt LED and you'll understand why commercial LED light bulbs are made of many smaller leds vs a single large one. Secondly you need to realize the heat put off by these LEDs is ridiculous, the heat sinks space required quickly puts a fixture made of these much larger, hotter, and more expensive outputting less light, than a simple fluorescent. Also these LED's do not have the long life of regular LEDs. Last you must look at the field of view for an LED. If the ones i found are the same as the ones you found then they aren't so bad at 110 degrees. 
The other thing that makes using one huge inefficient LED useless for planted tank enthusiasts is the color spectrum from the LED. a white led's spectrum is typically medium intensity in green sloping off towards red with a spike in blue. You'd be better off running the same wattage in individual LED's. 
Sorry for poor punctuation and spelling and everything I am very tired

This would be cool though - higher luminous flux than the brightest 24 watt T5 HO I can find online


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## redfishsc (Aug 29, 2010)

Zareth said:


> This is a misconception on your part. A 10 watt LED is going to be very inefficient. 10 watts simply means that it wants to be run at 10 watts, so you can figure out what resistors you need to use and what amps its going to pull.


You don't need resistors if you are using a constant current driver, which is the easiest way to drive these. You can build one yourself of course but I'd just prefer buy one already made.

You can get two of these 10w LEDs, complete with a constant current driver and pre-tapped heatsink and thermal compound for about $50. That's why I suggested it and it's STILL going to be more efficient than PC, CF, or even T5.

Did you look at the thread I posted? You talk about heat generated and so on. Look at the heatsink. After running for 8 hours, the heatsink doesn't get above about 120F at any spot, which is well within tolerance. I'd hardly call that problematic.

Yes, high power LEDs do produce more of a hot spot than those small 8mm/5mm LEDs but you're not going to come close to the efficiency of a Cree XPG/XPE using 5mm/8mm. At least, now with technology sitting where it does right now. They may develop 5mm LEDs later on that are more efficient, but as of yet.... I've never seen a datasheet claiming anything close to what a Cree XPG or Luxeon Rebel ES can do.













That 500 LED flashlight you linked to is cool also, but you suggested making a light with the same LEDs. Why would you criticize me for the 10w LED when you turn around and suggest using these same 5mm/8mm, inefficient LEDs over an aquarium?


My LED array over my aquarium uses Cree XPG which can produce upwards of 139lm/watt, which is nearly the most efficient commercially available LED out there. 


If you want to talk about efficiency, talk about Cree XPG, Cree XML, or Luxeon Rebel ES. At the moment, those three are about the most efficient LEDs out there.


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## redfishsc (Aug 29, 2010)

Zareth said:


> Compare the luminous flux of a 10 watt LED to a 1 watt LED and you'll understand why commercial LED light bulbs are made of many smaller leds vs a single large one.



Um. They both run around 70-100 lumens per watt. 



> Secondly you need to realize the heat put off by these LEDs is ridiculous, the heat sinks space required quickly puts a fixture made of these much larger, hotter, and more expensive outputting less light, than a simple fluorescent.



Nope. I have a 3 watt LED made from multiple small LEDs that is my car's dome light. I also have a stack of 3w Cree XRE and XPG. When driven at 3 watts (about 750mA) a single 3w LED throws of a considerable amount more visible light than the 3 watter in my dome light. 

Just to reiterate that several manufacturers of larger (3-10w) LEDs are hitting well over 100lm/wt. 

Please show me data that says these little LEDs can come even close to hitting 139lm/wt like an XPG. This is where the truth will be found.



> Also these LED's do not have the long life of regular LEDs.


50,000 hours isn't enough? Do the math, that's about 10 years at 8 hours per day. This is the projected useful life of a Cree.




> Last you must look at the field of view for an LED. If the ones i found are the same as the ones you found then they aren't so bad at 110 degrees.


They tend to run around 90-120 degrees and you can put optics on them for about $1-2 per optic to dial it down to 40, 60, or 80 degrees (and any number in between).




> The other thing that makes using one huge inefficient LED useless for planted tank enthusiasts is the color spectrum from the LED. a white led's spectrum is typically medium intensity in green sloping off towards red with a spike in blue. You'd be better off running the same wattage in individual LED's.


Useless? Really? So my array that's growing plants like crazy is just a hallucination? 

3W LEDs come in more color temps than even T5 and T8 comes in. 

Go ahead and dig around on google and dig up some spectral analysis of Cree XRE, XPE, XPG, or Luxeon Rebel, Rebel ES, or Rebel K2. Or Bridgelux 402. 


You'll find that they are VERY well tuned for photosynthetic purposes (especially the neutral and cool white).


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## redfishsc (Aug 29, 2010)

It all boils down to this. 

Show my any commercially available 5mm or 8mm (or 1-watt, for that matter) that can produce the 139 lumens/watt that can be done with a Cree XPG or Luxeon Rebel ES. 

If you find one, I'll gladly give them a try. 


A planted tank can definitely be run on 8mm, 5mm, and 1 watt LEDs. So I don't doubt that at all. 

But they are not nearly as efficient as a good brand 3w.


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