Minimalistic multichip DIY LED build

mr.wilson said:
It's hard to give advice on whether you have too much light, not enough, or the wrong kind of light without at least PAR values.

First off, your photoperiod should be 8-10 hrs and you are running between 3-8 hrs. Secondly, with no optics on any of these chips, you will not get adequate intensity for SPS. I use 100w multichips minimum for tanks that are 24" or taller. You are running an array of 10w multichips without specifying how close they are together. I don't have any experience with this kid of hybrid system, but in my opinion it gives you the worst of both worlds, the poor spectral distribution and shimmer of an array with the heat issues of a multichip.

Your generic chips may also have strange spectral qualities, as they rarely reflect the colour temperature numbers they are assigned by the manufacturer. I agree, a broader spectrum of blue light would help, but if I was to wager, I would say that you aren't getting enough light. Your new LED system is 400w and the outgoing MH was 1320. LED is more efficient than MH & T5, but you will likely need another 200w with smaller wattage multichips.

Perhaps someone out there has experience with these chips and can be of more help, but I haven't seen any colourful SPS tanks using them yet. I offer my apologies in advance to the 20 people who are about to post pictures of their colourful 10w multichip tanks :)

- add lenses
- increase photoperiod
- test PAR and raise or lower light accordingly
- possibly add more 50w or 100w chips
Click to expand...

I read around 130 to 150 in PAR at the bottom of my 2 feet deep tank with 10 Watts multichip without lenses so at that deep I should not put the more light demanding SPS. In this 4 feet long tank I use around 400 Watt LED. 130 watts with lenses but directed against the rock wall (at a deep of app 1 feet).

For the dull colors - test to rise the intensity of the white LED:s and take down the blues for a while.

I do not belive that the bleaching is caused by red light in this case.

However, my experiences is based on LED from another vendor.

Sincerely Lasse
 
http://www.flickr.com/photos/45627954@N02/7877281136/in/photostream

photostream


Thank you so much for everyone who helped this newbie out with his multi chip leds. I got most of the stuff from ac-rc and he was super helpful too. Awesome ebayer.

2 50watt hybrid rb and 10k chips with drivers from him also.

Sorry about the fugly looking tank still. Working on everything at once...from plumbing to stand building to rocks. I just need to concentrate on one thing at a time.
 
Lassef said:
I read around 130 to 150 in PAR at the bottom of my 2 feet deep tank with 10 Watts multichip without lenses so at that deep I should not put the more light demanding SPS. In this 4 feet long tank I use around 400 Watt LED. 130 watts with lenses but directed against the rock wall (at a deep of app 1 feet).

For the dull colors - test to rise the intensity of the white LED:s and take down the blues for a while.

I do not belive that the bleaching is caused by red light in this case.

However, my experiences is based on LED from another vendor.

Sincerely Lasse
Click to expand...

If you are getting 130-150 at the bottom without lenses, then 120˚ optics should bring it up to 200-250 where his metal halide & T5 was.

I agree, there is not enough red light in his fixtures to bleach corals, as metal halide has much more.

It's quite possible that there is simply too much blue light. Tanks with heavy blue light invariably have poorly pigmented corals. Greens, yellows and oranges show up great, but there is little in the way of blue, ed or purple pigmentation.

These bright colours may vary well be within the corals, but covered by a "lens" of green/brown zooxanthellae.

It's equally as possible that the cheap chips you have are way off the mark with regard to spectrum. You really get what you pay for with LEDs.
 
I currently have a 20K 50W chip over my smaller tank (36 X 20 X20)
and I'd say the color is more towards the 14K
right now I have only one chip over the tank about 10: high with no lens and everything seems to be doing well. I have an oval lens on order.

there are few SPS frags that appear to be doing well and a frag of a blue ridge coral that has nice polyp extension that I did not have in my 450 under mH lights
 
cree-rb.jpg xt-e-white.jpg​

Look at these two graphs - both shows spectrum from Cree XT-E. The first shows the spectrum from a RB LED at 450 nm. Picture two shows essentially the same blue LED, but with different phosphor layers applied. They both have the same output power, with the difference that much of the efficacy of the various white versions is located in other wavelength ranges than the original blue. The power output is the same on both - if where is a difference - it is less in the whites. A MH can be likened to the white LED with a continuous spectrum with more overweight in the blue region with increasing Kelvin.

If we look to the biological conditions, it is the blue wavelengths from 420 nm to about 460 nm, which is interesting for the majority of corals that grow deeper than about 3 meters. It is here that the main part of the photosynthesis takes place. if you have a traditional or white LED light source, you will see quickly that only about 1/4 to 1/3 of the wavelengths available in this area. We need to take three to four times more energy to get the same amount of the wavelengths of interest compared to if we take more or less monochromatic LED with peaks around 420, 430, 445 occh 455 nm.

But we do not see this, because of the human eyes poor ability to see these wavelengths in its full strength.

It easy to understand that we can give to much of this powerfull wavelengths and this is the reason why LED with much blue wavelenghts seems to be more effective than T5 and MH. The efficiency per watt inserted energy is not very much better (by today's LEDs) compared to T5 and MH but the quality of the light is right on target.

When we talking about wavelenghts around 420, there is another thing to have in mind. It is near the UV-A area (< 400 nm) and if the LED instead of 420 nm has their top at 400 - 410 - it is easy to get light that can harm our corals.

In the manufacturing process, it is sufficient with very small change of the ingoing materials to change the wavelength of the LED. I therefore believe that it is very important to precisely in the region around 420 nm to know the actual wavelength of the LEDs in use. Most manufacturers categorizes each bin (batch) for the dominant wavelength and a reputable supplier tells the dominant wavelength of their chip's.

There is a lot of reports according to corals sensitivty to UV radiation. Many of them produce special pigments just to protect themselves. Its take time so I think it is very important to start with low intensity in the blue area when changing from MH or T5 to LED.

Its basically the same for discrete emitters as for multichip with that the deviation that you often use high Kelvintal multi chip. As these already has high peaks in the blue region, its wise to be even more cautious not to start with too much blue light in the wavelength ranges from 420 to 460 nm. There is also a difference that the multichip produce more energy in a smaller area.

In contrast topTrea I'm more afraid of having too much blue light in a LED introduction than to have too much red.

There are some reports that talk about that some corals use red light to indicate that they are too high in the water and thus protect themselves from the intensity in part by reducing growth. I do not think it applies to all corals. See on this picture - it's acropora forests that at least once a day are exposed to high solar radiation

acro.jpg​

With some corals I´m no longer convinst that red wavelenghts is bad.

Sincerely Lasse
 
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pdfrogman said:
I currently have a 20K 50W chip over my smaller tank (36 X 20 X20)
and I'd say the color is more towards the 14K
right now I have only one chip over the tank about 10: high with no lens and everything seems to be doing well. I have an oval lens on order.

there are few SPS frags that appear to be doing well and a frag of a blue ridge coral that has nice polyp extension that I did not have in my 450 under mH lights
Click to expand...

sweet so it looks about 14k? more or less blue than say a phoenix 14k bulb?

also glad ho hear your corals are doing good :D very happy actually

how long have you been using that chip?

where did you buy it?

this info will be more helpful to me than you will ever know lol

at this point im planning on using 3 20k 100w chips on my 125g tank
 
joeogio said:
sweet so it looks about 14k? more or less blue than say a phoenix 14k bulb?

also glad ho hear your corals are doing good :D very happy actually

how long have you been using that chip?

where did you buy it?

this info will be more helpful to me than you will ever know lol

at this point im planning on using 3 20k 100w chips on my 125g tank
Click to expand...

been on tank about a month set up the smaller tank when I sold my 450
got the chips and drivers here

http://www.dealextreme.com/p/50w-3500lm-20000k-cold-white-light-led-emitter-32-36v-100744?item=14
 
Lassef said:
We have chosen that to channel 1 have 20 white LEDs at 10 000K, on Channel 2 have 20 RB 445 nm, on channel 3 have 10 Actinic 420 nm + 10 Actinic 430 nm, on Channel 4, we have 20 RB 455 nm, and the channel 5 additional 20 pieces white at 16 000K

The reason for the choice is two: growth and to be able to watch. The blue is selected considering various "chlorophyll's" absorption peaks. The white to provide additional wavelengths have other biological roles than chlorophyll, and that there should be an okay color rendition. The low intensity of the yellow-green region is chosen to disfavour organisms that use these wavelengths for photosynthesis. Sincerely Lasse
Click to expand...


This is an interesting combination. The issueI find with most led's is the difficulty filling in that gap from about 475nm to 505 nm. Every white chip I had seen so far has this as the lowest valey in its spectrum plot. Yet is is also morte important than some of the red and yellow wave lenghts that are seldom measurable in the ocean.
 
Lassef said:
If we look to the biological conditions, it is the blue wavelengths from 420 nm to about 460 nm, which is interesting for the majority of corals that grow deeper than about 3 meters. It is here that the main part of the photosynthesis takes place. if you have a traditional or white LED light source, you will see quickly that only about 1/4 to 1/3 of the wavelengths available in this area. We need to take three to four times more energy to get the same amount of the wavelengths of interest compared to if we take more or less monochromatic LED with peaks around 420, 430, 445 occh 455 nm.

But we do not see this, because of the human eyes poor ability to see these wavelengths in its full strength.

It easy to understand that we can give to much of this powerfull wavelengths and this is the reason why LED with much blue wavelenghts seems to be more effective than T5 and MH. The efficiency per watt inserted energy is not very much better (by today's LEDs) compared to T5 and MH but the quality of the light is right on target.

When we talking about wavelenghts around 420, there is another thing to have in mind. It is near the UV-A area (< 400 nm) and if the LED instead of 420 nm has their top at 400 - 410 - it is easy to get light that can harm our corals.

In the manufacturing process, it is sufficient with very small change of the ingoing materials to change the wavelength of the LED. I therefore believe that it is very important to precisely in the region around 420 nm to know the actual wavelength of the LEDs in use. Most manufacturers categorizes each bin (batch) for the dominant wavelength and a reputable supplier tells the dominant wavelength of their chip's.

There is a lot of reports according to corals sensitivty to UV radiation. Many of them produce special pigments just to protect themselves. Its take time so I think it is very important to start with low intensity in the blue area when changing from MH or T5 to LED.
Click to expand...

While I do agree with most of what your sayng here the last part I will disagree with. T-5's are more effecient than MH's, and LED's are more effecient than T-5's. In any of these light sources energy is consumed and converted to both heat and light. The ratio of heat to light is much more in favor of the LED as a light emitter, and much more in favor of a heat emitter in the MH.


Lassef said:
In contrast topTrea I'm more afraid of having too much blue light in a LED introduction than to have too much red.

There are some reports that talk about that some corals use red light to indicate that they are too high in the water and thus protect themselves from the intensity in part by reducing growth. I do not think it applies to all corals. See on this picture - it's acropora forests that at least once a day are exposed to high solar radiation

With some corals I´m no longer convinst that red wavelenghts is bad.

Sincerely Lasse
Click to expand...

I have read many reports of experiments in which red light mainly light longer than 600 nm creates bleaching of some species of corals. This seems to be especialy true of corals that rich in red pigments. However I will also agree that this does not include all corals.

On the other end of the spectrum there are actual corals that utilize light at 685nm in there photosynthesis process. These are very shallow corals as when you get down below 3 meters these wave lenghts barely exist, in the ocean.

The one thing that does concern me is the lack of light in 470 to 505 nm range from most LED's. While these are not prime photosynthesis wave lenghts there are many florescent chemicals found in some corals that do use these wave lenghts to floresce. As they floresce they actualy emit light in wave lenghts that are used by other chemicals in the coral for photosynthesis.

If anyone has done any diving they realize that the colors in the ocean bbecome a deeper blue as you decend deeper. The reflective colors of the corals lessen however the florescent colors pop out more so. If we stimulated the exact lighting of say 20 meters most people would be very unhappy with the appearance of there mini reefs. Therefore we add the "white" light to bring out the reflective colors simularly to the way most under water photographers suplement with high powered strobe lights.

The hard part is getting that balance between the monochromatic blue light found in the ocean and the "white " light that we add for our personal viewing pleasure. An access of that white light is not any better than an excess of the blue light.
 
TropTrea said:
This is an interesting combination. The issueI find with most led's is the difficulty filling in that gap from about 475nm to 505 nm. Every white chip I had seen so far has this as the lowest valey in its spectrum plot. Yet is is also morte important than some of the red and yellow wave lenghts that are seldom measurable in the ocean.
Click to expand...

Yes, but I do not think that these wavelengths (475 -and all the way up to 600) is so importantant in a biological point of view because we put much effort to offer the corals the right wavelenghts so they do not need to put in any energy to convert longer wavelenghts to shorter (this takes energy - the opposite gain energy)

However there might be other biological processes than photosynthesis using these wavelengths, for example at production of hormones or other. It means that i could be wise to at least have them with in some degree

Sincerely Lasse
 
The last sentens in my post became more incomprehensible than usual :) The following is probably more correct:

However there might be other biological processes than photosynthesis using these wavelengths, for example in production of hormones or other molecules. It means that it could be wise to at least have low levels of these wavelengths in the spectrum
Click to expand...

Regarding the efficiency of MH, T5 bulbs and LED. it is true that some LEDs have a higher effective rate in lumens per watt. However, this is a truth with modification. Cree XM-L Cool white group U2 provides about 150 lumens / watt at 1000 mA. At 2000 mA, the efficiency decreased to about 115 lumens per watt. These LEDs are designed for max 3000 mA and in practice there are few applications that use currents as low as 1000 mA with these LEDs.

The efficiency of multi-chip´s can at best go up to an efficiency similar T5 bulbs. Hence, the most important factors in order to save energy with LEDs is that the quality of the light is much better in terms of photosynthesis.

The bottom line with my post was to try to show that it is easy to put in to much power and it may therefore be setbacks and resulting destroyed coral´s.

Sincerely Lasse
 
TropTrea said:
While I do agree with most of what your sayng here the last part I will disagree with. T-5's are more effecient than MH's, and LED's are more effecient than T-5's. In any of these light sources energy is consumed and converted to both heat and light. The ratio of heat to light is much more in favor of the LED as a light emitter, and much more in favor of a heat emitter in the MH.
Click to expand...

Sorry, but that is simply not even close to being true. First of all A "T5" is just a fluourescent tube. It has rougly the same electrical efficiency as a T8 or T12 fluorescent tube. Its advantage is the small diameter allowing highly efficient reflectors to be packed tightly together. That is, it allows a higher Watt density over the same footprint as a T12.

Secondly, the "ratio of heat to light" is not in favor of the LED. In fact the LED directly produces far MORE heat than either a Metal Halide or a Fluorescent bulbs.


whitelight_new.jpg




As Lasse stated, the LEDs were are using are only as (if even) electrically efficient as MH and T5, the difference is in the wavelenghts they produce. Furthermore, the "warmer" the white light from the LED the less efficient it is, to the point that a CW LED has almost twice the efficacy of a WW LED.


If you are happy with the growth and look of 3:1 RB/CW than you can get away with far fewer watts becuase you are only producing light in those regions. As you start to add emitters to fill in the gaps, the wattage creeps up and the overall efficiency of the fixture creeps down.

Look at it this way, the MH lamp produces full spectrum with some light outside of the range we want or need (IR/UV). We are now trying to leverage LEDs to produce that same full spectrum without the IR and UV, but the LED produces more direct heat. However, there is no magic phosphor coating, so we need multiple LEDs to fill those gaps in. That means more Watts.

So remove 2 X 150W MH lamps (300W) from a 90 gallon tank and replace them with 180W of RB/CW cutting edge emitters for the crappy windex look, -OR- replace them with 250W of varied LEDs to get a broad spectrum output that looks good and grows coral well. In the end you replaced 300W of halide with 250W of LED. Your gain is 50W and the reduction of IR/UV that heat the tank water directly. You can maybe gain another few percent by ramping the LEDs up and down during the day to converve a bit more energy.

Now... If we agree that that same tank may be able to grow coral with 200W of metal halide lamps but look a bit dimmer, then we can assume that we could use 150W of broad spectrum targeted LEDs on the same tank and get a decent color rendering but not as bright as the 250W of LEDs. Nothing is "free", you grow coral but get a dimmer tank! Do it with JUST RB/CW and you get an even dimmer BLUE tank that grows corals for 100W instead of the original 300W of halide. But you are not comparing Apples to Apples. You have are comparing a BRIGHT CRISP COLORFUL tank with a DIM DULL BLUE tank. Some folks are OK with that, others are not.

LEDs are neat, but they are not magic.
 
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