MH v LED

Many LED companies claim that they are brighter than or as bright as a particular wattage MH. In most cases those comparisons are off. Especially those companies who are not using efficient (high lumen/watt) LEDs in their fixture. All LEDs are not created equally. An LED fixture is limited by how many lumens/watt the LEDs are producing. The lumen/watt efficiency of an LED can range from 4.5 - 150 lm/W. That is a huge range. Many LED makers will not let you know what LEDs are being used in their fixtures. I can tell you that any company using an LED that produces 80 lm/W or better is proud to share that info. Any LED company using a quality LED will put that info up front for you to see. They welcome you to research thier claims.

Compare a Boost LED 135 watt fixture and an 120 watt Orphek. One might conclude that the Boost LED product is just as bright as the Orphek since ithey have similar output. Compare the 70 watt Aqua Illumination who's PAR reading at 36" below the surface are equal to those reported by Boost LED's 135 watt fixture at 18" below the surface.

I guess what I'm saying is that without all the info, it is impossible to compare any lighting.
You need to educate yourself before making a choice.

 

thanks everybody... I learn a lot from this thread...

 

gcarrol is quite correct. The way to compare LEDs is to compare spectrographs, and then compare efficiency and spectral output.

FYI, a PAR meter isn't going to do this for you. PAR meters are only marginally useful when it comes to LED lighting, because they do not differentiate the PUR for corals from the rest of the PAR spectrum. This is why you need to be able to see the spectrograph of anything you might want to purchase. I say again: don't purchase anything you can't get the spectrograph for!

Pure electrical efficiency can be measured in lumens emitted per watts consumed. This info should also be readily provided before you make a purchase decision.

 

What specifically are we looking for on the spectrograph that tells us which are inferior and which are superior?

 

and this is based on . . . ??? Not sure if this is an opinion or fact-based statement (leaning toward the former)

 

Man that is one rambling contradiction after another . . . you go from "MH is the best and nothing beats it" to "if you have the money go for LED. . ."

The financial argument you make is about the only one I can agree with - LED's are more expensive.

The rest of that statement is not really clear. Are you perhaps actually trying to say that each lighting type has it's limitations and strengths? And that in your personal experience you have seen good growth from both MH and LED? You say you are getting good growth with SPS illuminated by LEDs which most ppl would consider to be the most light-demanding corals that one can keep. To me, this would indicate LED's ability to at least COMPETE with if not OUTPERFORM entirely, MH lighting. I am surprised you have not drawn the same conclusion when you yourself have presented the data.

Hence why I am unclear about the contradictions . . . .

 

+100 Make sense no.

Also, some random (and cheap) LEDs are a bad basis for comparison, as this thread has already covered...

 

It's a bit naive to compare an LED fixture using "narrower" secondary optics vs a fixture that uses slightly wider primary optics. One should also realize that for most tanks, spread is just as important as depth penetration.

We agree that LED spectropgrahs and LED efficiency are all important aspects of buying a fixture. However, I doubt many companies will release detailed technical specs on their LED's. If they were, I'd be interested to see all the techinical spec for the so-called PowerLED's in the Orphek units that were supposedly made with gold. Last time we checked their efficiency were merely average. :

 

Looks like in order to make a fair comparison of MH to LED's there are a TON more variables that can be "optimized" or "tweaked" with LEDs than with MH - this is just in terms of comparing the two with respects to light output - nothing to do with efficiency or fixture life - those are easy to compare - LED kicks MH's butt there.

With MH you have the ballast, reflector, and bulb to choose - that's pretty much it.

With LED there's a lot more to compile:

LED Diode - of which there are about as many choices as there are imaginations

Optics - the degree to which the light is directed using lenses as BoostLED states is CRITICAL to LED performance and can easily make/break a fixture.

Driver: there are CCV drivers and dimmable drivers. I guess there are for MH too but not nearly as commonly used IMO.

Color of the LED diodes - there is Cool White, Warm white, Royal Blue, violet, etc.

Ratio of different colors in a MPS (Multiple Point Source) light - all will create a diff. CCT and likely different PAR/PUR numbers.

It's important to look at all of the factors which can make an LED fixture strong or weak as the industry is in it's infancy. Small changes in the way the light is produced/focused can have enormous impact on the coral growth - which at the end of the day is the most important factor. The fact that LED's can do this in so many ways in so many applications with so many advantages leads me to believe MH will eventually be a thing of the past.


The question remains to be answered as to when this eventuality will be . . .

 

Aquaillumination puts their LED info on their website. They tell the brand of the LED and the series. Cree XPE and XPG. It's not hard to find efficiency info after that. What brand are you using? What is the efficiency in lumens per watt per LED? What is the total lumen output of your fixture? If you want I could refer you to someone who would be more than happy to bench test your fixture. He will gladly produce spectrographs for the fixture and output results that can be compared with other fixtures that he has tested.

Personally I do not think it is naive nor unfair to compare. If the LED efficiency is twice that of other brands, then they can easily be compared to LED units based on total output. Aqua Illuminations can be fitted with all wide angle lenses if you want and if total lumen output is greater than other brands, then effectively it has a highter output.

I find it interesting that you conside the efficiency of the Orphek average. Where do you rank the AquaIllumination? Where do you rank you MU series?

I'm not saying that there is anything wrong with your fixture, I'm just saying that there are other options and all different categories. I just feel that yours in not at the level of the Orphek, Aqua Illumination, Vertex and even the Maxspect.

I rank you with the Cad Lights, Blue Moon, and Evolution units. Nothing wrong with them as they all have their price point and audience. If I am wrong in this assessment, please let me know as I like many others am new to LED and I am trying to see which one will be best for me and my SPS tank. I currently own an Aqua Illumination unit, and a Vitrea (for my daughters' tank), I have ordered a new Ecoxotic 100w Cannon, I am looking into the Orphek and Vertex (if it come to America). I would like to play with them all before I make my final decision. I want a reason as to why I should go LED over my MH + T5 fixture or a ATI Powermodule on my next tank build.