What is the equivalent in LED to 400w MH?

I have sent an email to ecoxotic to get involved in this topic.

From my point of view this is a very serious topic. Lights are the life of the coral reef tank. If a vendor makes a claim that their product is a replacement for MH, and it is not capable of sustaining life of the reef inhabitants, then they are liable for damages if the tank should crash. So the science of the claims needs to be backed up by the vendor before I would make an investment that could potentially destroy my entire tank.

 

Well, it will be interesting to hear what they say. I certainly wish comparing lights was easy, however, as OrphekUSA said, "it's like apples to oranges". There are so many variables; Ecoxotic's statement may very well be accurate given a very specific set of variables and assumptions. However, that set of variables and assumptions may or may not apply to your tank or your goals. Companies don't need to make full disclosure regarding their claims and are free to be vauge; we don't live in that type of nanny state. The reality is it's up to you to make an informed decision.

IMO, though, as a consumer, I'd like to see manufactures publish actual output data rather than making broad statements.

Some do. For example, if we look at the Booste LED website, they have published output here: PAR30 LED Reef Lamps by BoostLED

If we look at the 40deg optics for example, you have around 400 PAR in the center, but it drops off very quickly. Within a few inches, your down in the two hundreds.

Still even with this, the interpretation is subjective. To compare this to a MH, we would need to do the same for the MH, but even MHs differ greatly. To make a comparison, we would need to define the height of the fixture, the coverage area, what we are measuring, i.e. PAR or some other metric and are we measuring the peak, or the average over a given area etc.... Then we still need to define the exact metal halide, what ballast, what bulb, what reflector etc... The reality, is without doing so, comparing any two lights, not just led to MH is like comparing " apples to oranges".


As for educating yourself and making informed decisions, there is tons of info out there, but that's good and bad, as there is tons of reading.... Remember, there probably wouldn't be tons of reading if lighting was simple....

Facts of Light – Part I: What is Light? by Sanjay Joshi - Reefkeeping.com

Facts of Light – Part 2: Photons by Sanjay Joshi - Reefkeeping.com

Facts of Light – Part 3: Making Sense of Light Measures by Sanjay Joshi - Reefkeeping.com

Product Review: Spectral Analysis of 400 Watt Mogul Metal Halide Lamps: Ushio 14000K, Icecap 400W Series, Elios 10000K — Advanced Aquarist's Online Magazine

Feature Article: Quantitative Comparison of Lighting Technologies: Metal Halide, T5 Fluorescent and LED — Advanced Aquarist's Online Magazine

Feature Article: LED Lighting Tests: Aquaillumination, Blue Moon, Eco-Lamp KR-91, Ecoxotic Panorama — Advanced Aquarist's Online Magazine

Product Review: Lighting for Reef Aquaria: Tips on Taking Light Measurements — Advanced Aquarist's Online Magazine

Feature Article: The Best Lamp Is... — Advanced Aquarist's Online Magazine

Product Review: T5 Fluorescent Lamps: UV Lighting's 'Super Actinic,' 'Actinic White,' and 'Aquasun' High Output T5 Lamps — Advanced Aquarist's Online Magazine

Feature Article: A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage — Advanced Aquarist's Online Magazine

Feature Article: An Affordable LED Luminaire for Reef Aquaria: Blue Moon Aquatic's 90-watt Fixture — Advanced Aquarist's Online Magazine

Product Review: A New Horizon in Lighting: PFO's Solaris LED System — Advanced Aquarist's Online Magazine

Product Review: A Comparison of Two Quantum Meters - Li-Cor v. Apogee — Advanced Aquarist's Online Magazine

Feature Article: Lighting the Reef Aquarium - Spectrum or Intensity? — Advanced Aquarist's Online Magazine

Feature Article: Effects Of Narrow Bandwidth Light Sources On Coral Host And Zooxanthellae Pigments — Advanced Aquarist's Online Magazine

Feature Article: PAM Fluorometer Experiments: Part I: Effects of Metal Halide Lamp Spectral Qualities on Zooxanthellae Photosynthesis in Photoacclimated Fungia Corals: The Red Light Theory and Part II: Effects of Water Motion on Zooxanthellae Photosy

Feature Article: Too Much Light! — Advanced Aquarist's Online Magazine

Feature Article: Playing With Poison - Ultraviolet Radiation — Advanced Aquarist's Online Magazine

Feature Article: How Much Light?! Analyses of Selected Shallow Water Invertebrates' Light Requirements — Advanced Aquarist's Online Magazine

Product Review: Aqua llumination's LED Lighting System: An 88-watt Sun for Your Reef Tank — Advanced Aquarist's Online Magazine

Facts of Light – Part 5: Everything You Need to Know About Metal Halide Lamps and Ballasts by Sanjay Joshi - Reefkeeping.com

Fun Times with a Quantum Meter, Part I: A Short Term Study of Various Practices' Effects on PAR Values by Brian Plankis - Reefkeeping.com

Lighting the Reef Tank: A Primer for Beginners by Doug Wojtczak - Reefkeeping.com

Light Output of the Phoenix 14,000K DE MH Bulb Over Time by Allen Chantelois - Reefkeeping.com

Reefkeeping's Product Review - Reefkeeping.com

Facts of Light – Part 3: Making Sense of Light Measures by Sanjay Joshi - Reefkeeping.com

Metal Halide Lighting Components by Jon Garner - Reefkeeping.com

Facts of Light – Part 2: Photons by Sanjay Joshi - Reefkeeping.com

Reefkeeping 101 - Ho! Ho! Ho! - Let

Testing 250-watt Single-ended Metal Halide Lamps and Ballasts by Joe Burger - Reefkeeping.com

Properties of Light by Andrew Trevor-Jones - Reefkeeping.com

Thoughts on Reef Aquarium Lighting

Underwater Lighting Conditions by Andrew Trevor-Jones - Reefkeeping.com

Facts of Light – Part I: What is Light? by Sanjay Joshi - Reefkeeping.com

 

Actually, the Ecoxotic 100w cannon has a wider spread that many metal halide systems. I have recommended to them that they decrease the spread a tad and they may have perfection. Right now the spread is approx 36" x 24" at a distance of 12". If they can get that same spread at a distance of 24" they would be right there with the MH. There also is not much of a hot spot as the light is pretty even due to the fact that they use a reflector as opposed to a optic lens.

I have the upmost respect for the crew at Ecoxotic! I know Ecoxotic will send their Cannon for review by Dr Sanjay Joshi so once they get the spread that they desire and the preferred packaging for hobbyists, I'm sure they will make this happen. Keep in mind that this was designed for the needs of public aquariums where light spread is king.

 

I hope they won't as they typically let their products performance do the talking. They have proven that their LED's will perform long term on captive reefs. They are unafraid to try unique color combinations unlike those who are just copying what is already on the market.

 

There is 2 distinct groups of buyers when it comes to reef products.
1. I just want to order a light that is healthy for my corals and I dont care about the specifics or the science involved.
2. I just gotta have the best of the best and I want the science to be proven and published so I can scrutinize it.

So depending on which camp you are in determines if you want the vendors to get involved in the discussion.

 

Now, you just said previously " What I have yet to see is an LED of that size provide that output and also provide the spread of a MH."

The cannon does have a wide spread for an led, 100degrees I believe, but that dosn't mean the light is consistent within that spread and you can't defy the laws of physics and produce light out of nothing. According to their website Cannon LED Pendants - Cannon Pendants - Aquarium LED Lights the Cannon "100W" consumes is 60W. So, let's pretend a 400W metal halide ballast is 400 watts.

We haven't defined efficiency... however, to say that a 60W led is equivalent to a 400W MH, if we hold all other variables constant, would mean that the Cannon is about 6.667 times more efficient (whatever efficient is).

Using any standard metric of efficiency, a 5 or 10% difference would be huge! Over 6 times more efficient, would not even be physically possible with any standard metrics of efficiency I'm aware of. To get more efficiency than that, again, holding all other variables equal, IMO, would require a fairly creative definition of efficiency and IMO this definition should be clearly defined if someone if going to use this claim to sell products. Saying "our 100 watt Cannons are quite similar in output to a 400 watt halide." does not provide any useful information whatsoever, unless you define the exact parameters used to justify that statement.

 

Keep in mind only a few companies have submitted their products for independent review. I am told this is going to change however until it does, the science put out their by the companies is definitely something that can not be confirmed. Until then, consider buying product from established companies with proven track records lighting successful reef tanks.

 

If it says 60w then that it is mistake. Possibly confused with the specs of the 50 watt Cannon.
Cannon LED Pendants - Cannon Pendants - Aquarium LED Lights
If you click on specs, you will find specs for the 100 watt and 50 watt (100w is just below the 50 watt specs). You seem to have only noticed the 50 watt.

FYI, The 100 watt is pulling 117w. Just checked it with the kill-a-watt meter for you.

 

Also keep in mind I never said that the 100 watt Cannon is comparable to a 400 watt MH but I can see the argument for it. Especially since they have replaced 400 watt MH units with cannons in public aquariums. I would put it up there with 250 watt MH's. As you can see from the photo above, the 12K has quite a blue tint.

 

Gotcha on the 100 vs 50w, thanks for the clarification. As to replacing the 400w there is a difference between being a suitable replacement and putting out the same total amount of light (i.e. Ignoring coverage area).

There are a lot of reasons it may be suitable, in addition to coverage area, you also have photosaturation, so perhaps some of the 400w light is being wasted etc...

However just considering total output over a wide spectral range the difference should be fairly small.


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