I think adding more leds than is needed for par is a good thing for a couple reasons: better light spread and the leds will last FOREVER at 500 milliamps!
DIY LEDs - The write-up
- Thread starter JohnL
- Start date
- Status
I think adding more leds than is needed for par is a good thing for a couple reasons: better light spread and the leds will last FOREVER at 500 milliamps!
Ok, I will grant you that.
True, but not entirely;
Although they're good value for money, the best to get at this moment, they are consuming close to 10 W to produce 1000 lumins.
When driven at 3A and fitted with 40 or 60° lenses, a good place to hang your your fixture at would be the ceiling of the second floor :lol2:
BTW, this is really an amazing thread, took me a month to get through all 389 pages (9327 replies) and links to other verry informative pages and websites.
Thanks to everyone providing this thread with all the important info we need to build our own fixture and for keeping this thread alive.
Last edited:
After advice from TheFishMan65 I have decreased number of LED for my new planned DIY light for 50"x24" 100g tank:
42 XP-E RB at 700ma with 24degree optics, - total about 100W
14 XM-L NW at 1500ma with 56degree optics - total about 66W
14 XM-L CW at 1500ma with 56degree optics - total about 66W
I plan to use CAt4101 DIY regulators 6 RB and 7 XM-L in strings. Therefore I need about 150W 17-22V powersupply for LED and about 200W 20-24V powersupply for XM-L. If it will be too much light I can lower it to 500ma for RB and 1000ma for XM-L.
by 24 or 56 degree optics I mean LEdil +-12 or +-28 FWHM (Full width at half maximum) optics, which means that by 12 degres there is 50% intensity of light compared to maximum 100% in center.
I will place it about 14" above the tank water surface and place LEDS in triangular grid 48"x23". I have simulated the blending for both RB and CW :
42 RB at 700ma with 24degree optics in Wats
at water surface
Already 2" below surface RB light should be nice blended.
In middle of the tank:
At the botton (20")
14 XM-L CW at 1500ma with 56degree optics in lux
at water surface
at 2" below surface
at 6" below surface nice blended
In middle of the tank:
At the botton (20")
I have ingored refraction and reflection. So the ligth should be stronger at sides due to reflection from tank glass sides. As you can see more leds and tighter optics brings more light into tank.
42 XP-E RB at 700ma with 24degree optics, - total about 100W
14 XM-L NW at 1500ma with 56degree optics - total about 66W
14 XM-L CW at 1500ma with 56degree optics - total about 66W
I plan to use CAt4101 DIY regulators 6 RB and 7 XM-L in strings. Therefore I need about 150W 17-22V powersupply for LED and about 200W 20-24V powersupply for XM-L. If it will be too much light I can lower it to 500ma for RB and 1000ma for XM-L.
by 24 or 56 degree optics I mean LEdil +-12 or +-28 FWHM (Full width at half maximum) optics, which means that by 12 degres there is 50% intensity of light compared to maximum 100% in center.
I will place it about 14" above the tank water surface and place LEDS in triangular grid 48"x23". I have simulated the blending for both RB and CW :
42 RB at 700ma with 24degree optics in Wats
at water surface
Already 2" below surface RB light should be nice blended.
In middle of the tank:
At the botton (20")
14 XM-L CW at 1500ma with 56degree optics in lux
at water surface
at 2" below surface
at 6" below surface nice blended
In middle of the tank:
At the botton (20")
I have ingored refraction and reflection. So the ligth should be stronger at sides due to reflection from tank glass sides. As you can see more leds and tighter optics brings more light into tank.
Finally my 65 LED in an old MH on u channel light. Getting there slowly. This is a 48 inch x 12 inch fixture, because the channels are close and I wanted to have a modular setup, the bars are same color leds, 3 royal blue and 2 white. The white are a 1:1 mixture of cool and neutral. I did sneak 4 regular blues in there also. I am not planning on optics, and I can get glass or acrylic cut a just slide it back in the existing channels in the fixture.
You can put two CAT4101 in parallel and then you get 2A.
The pictures were created in MS Excel, I have calculated how much light shines from each led to every point in 2cmx2cm grid at certain distance. This is Excel formula:
=LOOKUP(ASIN(SQRT((x_led-x_grid)^2+(y_led-y_grid)^2)/SQRT(depth^2+(x_led-x_grid)^2+(y_led-y_grid)^2))*180/PI() ,_lookup_table))*depth^2/(depth^2+(x_led-x_grid)^2+(y_led-y_grid)^2)
Lookup table is table containing calculated intensity of light as a function of degree at certain distance from led.
The pictures are two dimensional light intensity graphs at certain distance from LED lights. The x and y axis are in centimeters (2.54cm = 1"). The values are in wats for RB and in lux for CW. These value are calculated with 24 degree optics for RB and 56 degree optics for XML.
There is calculated 90% efficiency and no absorbtion by air not water. Also no refraction air/water and not reflection from tank glass sides. You can see triangular grid below. That means that each led in grid is in equal distance to six other leds (in orthogonal only to four). You can see the LED Grid below:
Last edited:
A Reef Scene
New member
Do you think that LED's will work in a tank that is 36 inches deep.
With proper optics they will work better than halides.
A Reef Scene
New member
I have luminarc fixtures with 400 watt bulbs. Would I need to make the LED's as large as the current fixture to get the same light coverage?
TheFishMan65
New member
You need to pretty much cover edge to edge maybe 3 inches in.
bourbeaue
New member
If you've bothered to get this far in this thread, it sounds highly theoretical that any of us would simply build a rig with today's technology and leave it alone... FOREVER.
IMHO most of us will continue tingkering with our setups over the years, trying out new LEDs and optics as they develop. This is way too much fun.
I am looking into building a led setup for my 110 gallon tank, its 48x18x30. With the tank being 30" tall what would be a good layout for this tank. Its a mixed reef setup right now.
I was planning on 6 rows of 12 for a total of 72 leds.
48 RB XP-E and 24 CW XP-G for a 2:1 mix.
The plan was 12" above surface. What do you think I would need for optics.
Thanks for any help
I was planning on 6 rows of 12 for a total of 72 leds.
48 RB XP-E and 24 CW XP-G for a 2:1 mix.
The plan was 12" above surface. What do you think I would need for optics.
Thanks for any help
As you maybe can see in my post above, it also depends what size your light will be. For 48 RB I estimate 30 degree and for 24 CW about 40-50 degree
S2minute
New member
Leds
Leds
Listen, natural sunlight on a clear day under good conditions is pretty freaken intense and corals on reef flats do just fine. You mean to tell me that the amount of LEDS some of us put over our tanks emit more lumens than Nat. sunlight on a reef? Impossible. It`s all in how you accumulate them. You can`t pack leds close enough to equal lumen output of the Sun on a reef flat. So if you bleach them, your not accumulating them slow enough. I`m i right or wrong? Even if it takes a year or more to bring your LEDs up to the level you want, do it.
Leds
Listen, natural sunlight on a clear day under good conditions is pretty freaken intense and corals on reef flats do just fine. You mean to tell me that the amount of LEDS some of us put over our tanks emit more lumens than Nat. sunlight on a reef? Impossible. It`s all in how you accumulate them. You can`t pack leds close enough to equal lumen output of the Sun on a reef flat. So if you bleach them, your not accumulating them slow enough. I`m i right or wrong? Even if it takes a year or more to bring your LEDs up to the level you want, do it.
S2minute, I see you point, I have calculated that using 200W if white led over 48"x24" tank you get maximum 40,000 lux on water surface if you put it approx. 14"-16" over the water surface. That means weak direct sunlight.
These numbers as from wiki:
10,000"“25,000 lux Full daylight (not direct sun)
32,000"“130,000 lux Direct sunlight
But we add also Royal Blue to tank and there is max. 50W of radiant flux of 450-460nm for 100W of Royal Blue and that might possibly bleach out the corals.
These numbers as from wiki:
10,000"“25,000 lux Full daylight (not direct sun)
32,000"“130,000 lux Direct sunlight
But we add also Royal Blue to tank and there is max. 50W of radiant flux of 450-460nm for 100W of Royal Blue and that might possibly bleach out the corals.
- Status
