LED lighting considerations

[mrg02d]

Hello all,
LED lighting is quite pricey. They can probably be built much cheaper. What are the things to consider for design? Seems to me that getting the LEDs are the most $$$ and hardest challenge. Powering them is simple. One just needs a current controller to drive the LEDs and a heatsink. Heatsinks are plentiful on ebay. An op-amp/MOSFET circuit can control the current through the LEDs. Seems to me one can save alot of money if they can solder, build circuits, and be okay without a snazzy enclosure.

1)How do LED power outputs relate to T5 and MH?
2)How close do the LEDs need to be clustered together? I am guessing that a tightly packed array would be much better than singles mounted in rows, but arrays are difficult to find and costly.
3)Are reflectors needed? Many LEDs have a tight divergence which means that are more like beams than point sources.

Matt

 

[melosu58]

Moved to the General Hardware and equipment discussion.

 

[Kurt_Nelson]

You will find more information than you could ever want about DIY LEDs on this thread...

DIY LEDs - The write-up - Reef Central Online Community

Only attempt to read it when you have several days to devote to it. I lost track of how many times it split.

 

[cmor1701d]

Finding LEDs in the right wavelengths and then optimizing for coral growth are probably the hardest parts. Then you need to decide on 1w or 3w versions, and if you want to control your lights instead of having just a manual on/off.
I wanted to get the Solaris unit a couple of years ago because it offered just about everything I was looking for in a nice package. Once they brought manufacturing back onshore the problems seems to have been resolved, until they were forced out of business by a patent suit.

I then started lookng at MH and I was considering the Giesemann Moonlight Infiniti 3x250W HQI + 4x80W T5 Light Fixture which had some great software controls. I was looking at a 1 year old fixture for a 1k less than list.

Then I found the PacificSun BT EX units on presale. LED units with the equavalent of 400w MH and fully controllable for sunrise/sunset/moonphase, or 40 points of customizable power. These were units with 120 - 1w LEDs. They have also come out with a 3w unit with 54 LEDs per unit. They offer refelctors for the 3w units with varying degrees of focus. The 1w are about 120 degrees.

Yes they are expensive, but when I considered buying all the parts and the time it would take (time I don't really have), I splurged and bought these units. I couldn't be happier.

I use less make up water, and less electricity to power them and I don't need fans to cool my tank, so my tank temp is extremely stable now.

Read through that thread on RC if you are really determined to DIY. It would have been a fun project if I had the time to devote to it, but I needed a new fixture NOW and figured I needed 4-6 months to build one.

 

[mrg02d]

Wow, getting ahold of suitable color temperatures is very difficult! Readily available LEDs seem to max around 6500k. High bias voltage also means that the driver will have to work at much higher voltages.

It does seem that the biggest problem is finding the LEDs...Id figure 3W diodes in the 12,000k - 14,000k range would be ideal.

Anyone know a good source of suitable LEDs?

Matt

 

[cmor1701d]

I'm pretty sure some sources can be found in that thread that Kurt linked to. I spent a lot of time reading it with my buddies before deciding against the DIY

 

[Bige]

The tech is advancing very quickly. 1w and 3w are low by new products. There are 5w and 10w. The 5w and the 10w have cooling fans built into the tops. All you need is white and blue but green can be used to bring out more color. The only place I know to get them is on ebay. They are made by chinese companies. But those are 100%DIY. I have a 100% led biocube and I am very pleased. You need to look up led DIY builds on internet. There are forums dedicated to the electronic builds. There is a guy named evil66 how is the "guru" and he will help you himself. Just find his forum.

 

[cmor1701d]

Take a look at the Rohm site to get some typical wavelength output for different LEDs. You'll see that the BLUE leds are arouond 460nm whcih is above the 420nm of 03 Actinic light. Trying to to find the right combination takes time and patience and probably a few emails or phone calls.

 

[AMDPhenomX4]

Go for high bin Cree XPG's or Luxim Rebels. The best bins have the lowest variance on the 6500K color. As for drivers, someone on reefcentral made a DIY one which drives and dims 3x6 led sets at 700mah each. They cost around 15 each or less to build. As for the blue LED's go for CREE XP-E Royal Blues. On the note of LED's from random china brands, usually 5W and 10W leds are junk with high degradation rates. The CREE leds degrade 5% per year, while the china brands may as well as being off color, have 10% or even higher degradation. I've researched long and have found the XPG with optics or Rebels with optics the best.

The drivers are easily controlled with an arduino and their is also a 2X8 3W led driver. The arduino can allow functions similar or the same as the pacific sun with enough coding.

If you rather not DIY the fixture, these brands are the best I know of.
Pacific Sun-High power using brute force of 1W led's. Most advanced with seasonal and lunar cycles, and temperatures of each. Weather effects and bluetooth. These cost around $1000 each with slave units being cheaper.

Maxspect-Good amounts of PAR equal to a 250W halide. The spread of the fixtures is 2X2 feet. The cost is around $500 and $700 depending on size. They cannot dim but have 3W semileds and 30W off brand LED's. The power supply has timers for the 30W, White 3W and Blue 3W.

Aqua Illuminations-Crazy PAR but with less spread versus the maxspect or the pacific sun due to optics. Its spread is around 2FT by 1Ft. The light uses CREE XPG and XRE with a 2:1 ratio. Their are a total of 24 LED per fixture and have dimming and controlling. It is basic controlling with color spectrum change and on off times. At over $600 each, they cost almost double than the other 2 options. They do however put out around Double the par or more. These are the only US based LED lighting due to their licence with orbitec.

 

[mrg02d]

SO while I keep an eye out for a good reliable source, let me get the idea down of what needs to be done.

1)Layout of the LEDs. Should I put a bunch together all in a small area, or should the be spaced out? I would plan on 3W diodes. Would replicating a T5 layout be better than say a metal halide setup?

2)Power. I have a 20g tank. I am currently running a 96w, 4 bulb T5 setup with two 12000k bulbs and 2 460nm bulbs. Should I shoot for 96W of total LED power (or how ever much I can afford?)

3)Color. Should half be 12000k or so, and the other half 460nm or so?

Ive already got a working driver that I use for powering high power laser diodes. (I used expresspcb to make circuit boards). I could just assemble one for each string of leds required. Each driver has its own op-amp and MOSFET to control the current through each string of diodes. Easily dimmed (by manually turning a trimpot, but a computer could be used to do this instead as current control is done via voltage division on one op-amp input). I could dim each string indepenent of each other for different effects!

Thanks guys!
Matt

 

[AMDPhenomX4]

If you did 96W on that tank, it would cook your corals. Go for a mix of 6500k and 460NM and dim to your liking. Theirs pure white in the 6500k not yellow like in filament lights.

 

[mrg02d]

Cook them? Ive been running the 96W T5 light for months now.

I figured they would like some more light actually...

Arent 6500k bulbs much more yellow? I favor the blueish bulbs actually. I am currently running 12000k bulbs with some 460nm bulbs. Still doesnt look white enough to me. Everything looks brown and rusty. More yellow...:-(

Matt

 

[mrg02d]

Okay, so from what I underatand, I could use 6500k and some 460nm blue to get what I am at right now. (12000k + 460nm T5 lamps). I favor the blue end of things. (White with some blue).

Looking around, these LEDs are $$$$ as heck! Im seeing prices in the $15 range for a luxeon mounted on a star and thats for the 3W led. How many would I need for acroporas in a 20g tank? Im guessing 60W would be a good area to shoot for. That would mean 10 6500k and 10 460nm? That would place me WELL over the maxspect price for a 60W setup! Seems rediculous to do such a thing with something out much cheaper. Anyone know how reliable those Maxspect setups are? Id hate to spend $200 and have it fail a year later.

Thanks!
Matt

 

[AMDPhenomX4]

24 Premium LED Do-It-Yourself Retrofit Kit That or the 12 LED version.

 

[cmor1701d]

So that kit is 24 x 3w Cree LED's? The PacSun 3w units have 54 x 3w Cree LEDs per unit. Again the price difference between DIY and ots is pretty small. Add your time and it becomes a labor of love.

 

[AMDPhenomX4]

The pacific sun is almost $1000 dollars.

 

[mrg02d]

Yea, and the Maxspect seems to be only offered outside the USA. Id have to spend $158 just to ship it to me! Thats over $300.00 for a low end LED system. I think this all was a great lesson to wait! Haha! Even DIY will cost me a good bit for the LEDs alone! My drivers cost me about $40 to make too. Id need one per strip of leds. Then I would need to buy heatsinks. After all that, Id feel left out since my drivers only power the LEDs rather than do anything fancy like color mixing. :-(

I think I will stick with T5s for some time.

Thanks!
Matt

 

[AMDPhenomX4]

Actually, i think you can get the maxspect for around 200 to your door. On manhattan reefers, the group buy is 190 shipped to your door.

 

[mrg02d]

Okay, it does appear there are some USA suppliers, but they require 20 day build time for the 60W. I am looking over the 60W details, (Im thinking the 60W is more than plenty for my 20g reef with SPS right?) and the 60W doesnt seem to be really worth it. It offers very little really, but still costs $160 and uses inferior LEDs. Really isnt much more than a snazzy enclosure with some LEDs inside. I could do that, but I have a bad habbit of using quality stuff and that drives the cost up. The 110W version is much better, but I cannot justify $400.00 on a system using cheap LEDs, and for a 20g tank. Too bad it has to more than double in price for only 50W more...They ought to leave out those large diode arrays. They cost more and as pointed out earlier, arent nearly as reliable.

Still seems that T5s are much more cost effective right now. Im sure in a few years, everyone will have LEDs.

Still keeping the DIY spirit alive, arent the CREE leds 6500k? Isnt that much too yellow? I have some acroporas, and like the blue colors. I am looking for crisp white with blue tones. I can tell you, I HATE yellows and pinks! Makes my tank look filthy! (Hate the URI T5 bulbs, all cast pink light!)

Also, at what point does lighting cook the tank? I am assuiming that putting on that 110W maxpect would cook a 20g?

Matt