Minimalistic multichip DIY LED build
- Thread starter maglofster
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TropTrea
New member
If I'm reading the specs correctly that heat sink should be able to handle about 225 Watts of LED's without running fans. Whit fans you could probably push that up to a little over 300 watts. With your 8 X 20 Watt LEDs this should work nicely.
TropTrea
New member
For Salt water it realy is not advisable to add a lot of RED's. If your using Neutral Whites you will have more than enough red. It is only on 10,000K to 20,000K that the red is lacking. But you need to keep in mind that RED in the 685 nm range as been known to cause coral bleaching and outbreaks of cyno bacteria.
A majortiy of the corals we use in aquariums come from levels in the ocean where they naturaly receive very little red light if any. Therefore there is little if any chlorophyl A in these corals. Fresh water plants live near the surface and they have an abundance of chlorophyl A. So fresh water plants do need Red light but not most corals.
mrbncal
New member
It sounds like he is putting it on a freshwater tank.
DrawnToBeaches
New member
Yup I am, and most of the plants are already red so they reflect the red light not sure if I will really need it
I was looking at one like the below. It says series, but looking at it, there are no traces, so, my thought is that it's really just a mounting base for LED's and you wire them however you like.
http://www.ebay.com/itm/wdm-2x12-1W...956?pt=LH_DefaultDomain_0&hash=item2a19472b3c
Actually, that one might really be series, and be painted over the traces (which presumably you could cut, but, meh). This one however, looks perfect:
http://www.ebay.com/itm/wdm-5x-RGB-...322?pt=LH_DefaultDomain_0&hash=item2a1a8eeeea
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Lassef
Member
Green plants have two major absorption spectrum peaks in the red area - around 640 and 660 nm. These peaks are important for chlorophyll B and A. (B around 640 and A on 660). The corresponding peaks in the blue area is 450 for B and 430 for A. As TropTrea says this is usually not the red zone so interesting for coral because the red wavelengths are effectively filtered out of the water. Freshwater Plants need, however, these wavelengths. But if you primarily have red plants so are the red wavelengths are not significant because these plants often have chlorophyll with other absorption peaks than those in the red zone - but the green freshwater plants need red wavelengths of approximately 640 and 660 nm. How you in a good way mixes up the various light sources is a problem I can not help you with - that you must experiment with by yourself
Sincerely Lasse
DrawnToBeaches
New member
Then do you think I should just go with a 6000k-6500k emitter? I hate what it looks like but if 10000k is lacking in red I might as well just get one emitter
Lassef
Member
See it this way:
You need a certain concentration of the specific wavelengths that the organisms that use photosynthesis need. It can be solved in two ways. Either you put all the power (Watts) just at these wavelengths, or use more light from a source that contains less of the relevant wavelengths. In the second case you need more power than in the first case to obtain a sufficient amount and intensity of the relevant wavelengths.
This is why the LED is the most efficient compared to other light sources. You can concentrate the power where you need it.
If you use only white light with no special blue and red light sources in the appropriate wavelength ranges, you need to put more watts to get enough of these wavelengths. A light source with 6500 K contains usually (note usually) more red and less blue light than one of 10 000K. If the red wavelengths are important to you, you have to put more watts if you use 10 000 K than using 6500 K.
In your case it will probably 10 000 K to be good. However, it may be wise to check which wavelengths your red plants need.
If it turns out you do not get the effects on growth as you expected at 10 000 K - Then you can choose from to complement the with light sources in the specific wavelengths range - or you can increase the wattage of your existing light source and thus get more of the desired wavelengths.
This thread is not about fresh water but I think it is important to address the above, since the logic is applicable to blue or white light in a coral reef aquarium.
Sincerely Lasse
You need a certain concentration of the specific wavelengths that the organisms that use photosynthesis need. It can be solved in two ways. Either you put all the power (Watts) just at these wavelengths, or use more light from a source that contains less of the relevant wavelengths. In the second case you need more power than in the first case to obtain a sufficient amount and intensity of the relevant wavelengths.
This is why the LED is the most efficient compared to other light sources. You can concentrate the power where you need it.
If you use only white light with no special blue and red light sources in the appropriate wavelength ranges, you need to put more watts to get enough of these wavelengths. A light source with 6500 K contains usually (note usually) more red and less blue light than one of 10 000K. If the red wavelengths are important to you, you have to put more watts if you use 10 000 K than using 6500 K.
In your case it will probably 10 000 K to be good. However, it may be wise to check which wavelengths your red plants need.
If it turns out you do not get the effects on growth as you expected at 10 000 K - Then you can choose from to complement the with light sources in the specific wavelengths range - or you can increase the wattage of your existing light source and thus get more of the desired wavelengths.
This thread is not about fresh water but I think it is important to address the above, since the logic is applicable to blue or white light in a coral reef aquarium.
Sincerely Lasse
DrawnToBeaches
New member
Thanks a lot lassef, I'll be running this on a 116g cube now so I'll probably be running at 2200ma or somewhere near, if I run into growth issues I'll add a couple red emitters and dim the 10000k back to under 50w youve been a great help thanks
miatawnt2b
New member
are there any spectrum plots for the 10k, 14k, and 20k multichips? I am struggling with the idea of having to use multiple chips over my 18" cube. I'd much rather do a single 50W chip and be done with it. There are also these hybrid chips to think about, but it seems silly if the 14k chip has nice color and peaks at 450nm.
-J
-J
joelespinoza
New member
How hot do these run usually? I got this little guy: http://www.ebay.com/itm/27093535093...NX:IT&_trksid=p3984.m1439.l2649#ht_1603wt_905 it is listed at 2100mA and I am running it at 2000mA and that little guy is hot to the touch. I am running it on a small CPU heatsink (like 65-90 watt AMD aluminum heatsink) with arctic silver thermal adhesive, and the heatsink and the other LEDs stay perfectly cool, but that sucker is getting toasty. Is this normal?
I was going to order one of those too, can you post a picture of it on your tank?
joelespinoza
New member
Here is one I just snapped from my chair, the tank is still in the mockup process. I actually wont be using this tank but will instead order a new one just like it.
This is 4 Phillips Luxeon 3w LEDs from stevesleds (1 neutral white and 3 royal blue) and the one 20 watt 420nm chip, it looks much nicer in person, it seems incredibly bright in this picture, I assume the camera is actually seeing some of the light heading into the UV range that my eyes dont.
EDIT: Here is a slightly better pic, keep in mind this tank is actually pretty scuffed up, thats why I am getting a new one:
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joelespinoza
New member
I would not advise buying this chip: http://www.ebay.com/itm/27093535093...NX:IT&_trksid=p3984.m1439.l2649#ht_1603wt_905 , I dont know how soon it will burn out but I have tried everything I can.
I first tried arctic silver thermal adhesive on my 65-90w stock AMD cooler, the heatsink never even got warm but running the chip at 2000mA (when it is rated for 2100mA) caused it to get hotter then hell, even at 1000mA it was uncomfortably hot. I shut it down and took it off, cleaned and lapped both sides and reapplied the paste in a very thin layer, same result.
Then I got serious and I got out a heatsink I have that has a solid copper core, of about an inch in diamater, I cleaned the chip off again, exposed the copper under the silver colored plating on the bottom of the chip, put a thin smear of flux on the copper heatsink and the copper chip and put some flux and silver bearing solder (63/36/2) between them and soldered them together (not an easy feat while balanced on the washing machine)
Still no dice. This chip still gets blisteringly hot almost immediately when hooked up to a 2000mA driver, and will still burn my fingers even at only 1000mA.
I first tried arctic silver thermal adhesive on my 65-90w stock AMD cooler, the heatsink never even got warm but running the chip at 2000mA (when it is rated for 2100mA) caused it to get hotter then hell, even at 1000mA it was uncomfortably hot. I shut it down and took it off, cleaned and lapped both sides and reapplied the paste in a very thin layer, same result.
Then I got serious and I got out a heatsink I have that has a solid copper core, of about an inch in diamater, I cleaned the chip off again, exposed the copper under the silver colored plating on the bottom of the chip, put a thin smear of flux on the copper heatsink and the copper chip and put some flux and silver bearing solder (63/36/2) between them and soldered them together (not an easy feat while balanced on the washing machine)
Still no dice. This chip still gets blisteringly hot almost immediately when hooked up to a 2000mA driver, and will still burn my fingers even at only 1000mA.
Lassef
Member
There must be something wrong. I have the same chip an a 405 nm UV chip mounted on a 400 mm (15.75 ") long square aluminum tube (50 * 25 mm - 1.97" * 0.98 ") with a 50 mm fan blowing into a hole from the upper side of the tube. At 1.8 A, I get a temperature of about 40 degrees Celsius (104 F) at the heatsink and it's a total of about 36 watts.
It is the temperature at the back of the chip and the heatsink temperature you should worry about. If you put your finger on the front of the chip - when you burn yourself - but it is so with all types of chips.
With my 10-watt chip that has worked for nearly 1.5 years, I can not tuch at the front but my heat sink temperature is around 35 degrees C (95 F)
Sincerely Lasse
It is the temperature at the back of the chip and the heatsink temperature you should worry about. If you put your finger on the front of the chip - when you burn yourself - but it is so with all types of chips.
With my 10-watt chip that has worked for nearly 1.5 years, I can not tuch at the front but my heat sink temperature is around 35 degrees C (95 F)
Sincerely Lasse
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ravi197699
Member
just a question i am building diy led build i am getting 6 50w hybrid led which carry 30 chips of blue 465nm and 30 chips of 20k. with these lights i will be getting 30k color temp and i have some meanwell dimmable drivers i will be using those to run some red's and greens and i have fan clooking my heat sink with these and drivers for 50w led comes with pwm 0-10v signal which i can controll with my neptune apex. i am planing to use this with 90 deg optic but how far the optic has to be from led to get 90 degree angle? i will post pics of during and after the built.
Would a single 100w 20000k multi chip be enough light for a 60 gallon 2 foot cube (mixed reef)
I was looking at the following items and wasn't sure if it was enough or to much. I'm wanting to replace a 250w de halide fixture with a Phoenix 14k bulb. Any help would be appreciated.
http://www.ebay.com/itm/100W-20000K...978?pt=LH_DefaultDomain_0&hash=item3f0f68e002
http://www.ebay.com/itm/85-265VAC-1...ultDomain_0&hash=item33750fce5b#ht_1346wt_689
Also has anyone used the housings that Ac-rc sells for drivers? I'm curious if there worth the few bucks or better to go with a project box. Also if their worthwhile, what size?
I was looking at the following items and wasn't sure if it was enough or to much. I'm wanting to replace a 250w de halide fixture with a Phoenix 14k bulb. Any help would be appreciated.
http://www.ebay.com/itm/100W-20000K...978?pt=LH_DefaultDomain_0&hash=item3f0f68e002
http://www.ebay.com/itm/85-265VAC-1...ultDomain_0&hash=item33750fce5b#ht_1346wt_689
Also has anyone used the housings that Ac-rc sells for drivers? I'm curious if there worth the few bucks or better to go with a project box. Also if their worthwhile, what size?
