why not?

[mainereefer]

When comparing LEDs and fixtures its a bad idea it compare wattage.

Not all LEDs are the same. I like the Cree XT-E and XP-G. They are 5 watt LEDs but when driven at 2 watts or 700mA they are much brighter than most 3 watt LEDs driven at 700mA
With quality current generation 5 watt LEDs one could easily duplicate the PAR of a 250 watt MH with a 30 Royal Blue and 15 Cool white. I've measured around 420 PAR at 24" using only 120 watts.
This is the Growth
Then take the MH graph of your favorite Bulb and toss in a couple spectrum specific LEDs to replicate the colour and looks perfectly.
I've done this with my personal tank and really like the result.
Bill

so you are saying to make a fixture with 40-5w led and run it at 120w?
see this dosnt make any sense to use a 5w led and run it at 2w most 3w led only run at 2.3w

with my led light I built it puts out almost the same par as my mh light, but my corals still lean to the mh. the reason for these questions.

I want the same colors coming out of my led as my mh without 6-7 dimmers for all 3w or 5w led then have to guess where they need to be dimmed to because I have never met a hobbyist with a spectrometer. I want a combination of led color and wattage with one dimmer!
I am now guessing it cant be done or ppl dont know how to do it, maybe it would be to hard? dont know all I have gotten is the run around with the same old, same old
there is no way you can tell me 2 specific colors of led make up the whole color spectrum of a mh!! led are color specific meaning they only emit a certain color. that tells me you need multiple colors of led, and the reason led light makers are putting multiple colors of led in there fixtures

I am saying these multiple colors of light need to be different intensities to equal the output of a mh .

cree led may be the most efficient power wise, but saving 300ma dosnt matter when your trying to replicate a light with multiple colors they dont make. anyway bridglux it is still way more efficient than a mh and they make the colors we need for our aquariums
I cant make my corals settle for the "better" light if it isnt better just a little stronger of the wrong color

AGAIN WHY NOT HAVE A LIGHT WITH MULTIPLE COLORS AT DIFFERENT WATTAGE'S TO REPLICATE SPECTRUM COLOR OUTPUT OF A MH,AND PUT ONE DIMMER ON IT TO DIM IT FROM SAY 400W OUTPUT TO 100W OUTPUT .

 

[ReefLEDLights]

It makes perfect sense to run a 5 watt LED at 2 watts or 700mA.

They are more efficient when underdriven. At over 70% they produce a lot more heat and not much more light.

The prices of 5 watt XT-E LEDs are now less than the 3 watt XP-E LEDs common last year. Then there is driver cost to consider.

Look at it like driving in Montana with no speed limit. Most people drive between 70 and 90 mph not 150

Lighting and duplicating a specific MH Bulb is as simple as a recipe. The challenge is to find the right one.

Once you have the right mix given the Vf and max current of the LEDs its perfectly fine to mix them on the right driver and use a single dimmer.

 

[mainereefer]

ok even if you run a 5w led at 2w it is still a 2w light like the rest of the 3w led. I am saying any wattage led the re are certain colors that need to be stronger than others.
led are color specific so you have to have to have a different led for each color (unless you get multi-chip)

so why are led lights made with different colors ran at the same strength with the same optics? this gives color spikes in the wrong color's that give us lack of growth or lack of color in corals or to much of a color to look at, corals loosing certain colors, bleaching ....

even if it was all 5w led run at different levels of power with limiters why isnt anyone building lights that are equivalent to a mh in color spectrum?

I can buy a fixture that looks to the eye like 15k or 20k but if you look at the actual color the led light puts out it isnt even close

 

[ReefLEDLights]

ok even if you run a 5w led at 2w it is still a 2w light like the rest of the 3w led. I am saying any wattage led the re are certain colors that need to be stronger than others.
led are color specific so you have to have to have a different led for each color (unless you get multi-chip)

so why are led lights made with different colors ran at the same strength with the same optics? this gives color spikes in the wrong color's that give us lack of growth or lack of color in corals or to much of a color to look at, corals loosing certain colors, bleaching ....

even if it was all 5w led run at different levels of power with limiters why isnt anyone building lights that are equivalent to a mh in color spectrum?

I can buy a fixture that looks to the eye like 15k or 20k but if you look at the actual color the led light puts out it isnt even close

One could easily argue the recipe to create the same spectrum of and given Halide. I personally like the look of the Radium Bulb. 24 Royal Blue 6 Blue and 15 Cool White comes awfully close in both spectrum and looks.

By tossing in a couple Green or Red and a few more Cool Whited one could easily replicate the 14K Ushio.

One point that should be stressed is the spectrum between 420 and 465nm grow coral quite well and has been documented. Adding other colours to the mix is for mostly for looks. Although with enough tweaking of an LED Array one could replicate copy of any MH Bulb based on a spectral chart. This in unnecessary as both growth and looks are covered with the common LED recipes out there like in the Radium. One could improve even these looks with binned LEDs. This is why I like DIY.

Multichip has promise but the spectrum is only based on 4 LEDs which is like only using four different LEDs in a build and for now the cost of four separate LEDs is less and one would choose more Royal Blue and Cool White with a lot less Red and Green.

IMHO The cumulitave average of all LEDs determine looks, the total number of spectrum specific LEDs determine growth as well as looks.

Bill

 

[mainereefer]

One could easily argue the recipe to create the same spectrum of and given Halide. I personally like the look of the Radium Bulb. 24 Royal Blue 6 Blue and 15 Cool White comes awfully close in both spectrum and looks.

Bill

this is almost what I used except I used cold whites instead of cool whites. maybe this is why they like the mh better than the led? although my par 2" under the led is around 3000 I would post pics with the par meter, but I sold my meeter to this guy who sells some nice led lights

I am building the light for my nanocube (still confused). I think I will try to use a 10w cold white, 8, 5w royal blue with some 1w r,g,b all on one dimmer. we will see how this works out maybe the future of led fixtures

 

[ReefLEDLights]

this is almost what I used except I used cold whites instead of cool whites. maybe this is why they like the mh better than the led? although my par 2" under the led is around 3000 I would post pics with the par meter, but I sold my meeter to this guy who sells some nice led lights

I am building the light for my nanocube (still confused). I think I will try to use a 10w cold white, 8, 5w royal blue with some 1w r,g,b all on one dimmer. we will see how this works out maybe the future of led fixtures

Please post results.

I really like the Cree Cool White as its full spectrum less the Red

My nano choice is Cree XT-E with 10 CW, 12 RB w 3 Blue on two dimmable drivers.

Reds and Greens are highly debated...But can easily be added into the mix.

Looking forward to some pics.

Bill