Last Updated 6-7-13
With LED Lighting advancing at a fever pace, there is a lot to know and as well there is a lot of good information available, but there is also a lot of bad or simply misleading information too.
- PAR (Photosynthetically Active Radiation)
- PUR (AKA Useful Light Energy)
- Other LED Considerations/Rumors
- Unique Features; Lightning Storms to Stimulate Breeding
- In Summary
- TMC AquaRay Recommendations
Lets start with CRI (Color Rendering Index), this is what OUR human eyes see, not necessarily what is best for Corals or Plants.
Unfortunately even some of the best LED manufacturers as well as those reviewing LEDs, such as an otherwise very good Aquatics Blog post I read recently, tend to give way to much credence to the importance of CRI as to Aquarium Lighting.
Also many who purchase a good LED light will look at their new light and then compare it to an existing T5, Metal Halide, or similar and then complain that the LED is not as bright. This is again based on the fallacy of depending upon the narrow band of light our eyes can see.
Among the few LED’s that do not depend upon CRI ratings, rather with the most accurate essential light energy for Reef or planted aquariums currently on the market include the TMC AquaRay or Orphek.
More specific to CRI, many purchasing or reviewing LED or other Aquarium Lights look to CRI as to how their corals or fish look under specific lights, and often those lights with higher CRI will show of certain colors better than other lights.
While this is all well and good, this should not be used other than maybe a minor consideration when purchasing an aquarium light, in particular LEDs.
The symbiotic zooanthellic algae living within corals, clams, etc do not “care” how they look to you, but their biological needs are important when it comes to “Useful Light Energy” (PUR) & PAR, so these parameters should be more important to you.
In other words, having LEDs that allow for RBG features does little when it comes to supporting photosynthetic reef or planted aquarium life!!
Photosynthetically Active Radiation is the spectral range of solar light from 400 to 700 nanometers (some research indicates up to 750nm) that is needed by plants & symbiotic zooanthellic algae for photosynthesis.
Although LESS important for determining which LED Light to purchase than “Useful Light Energy/PUR” it is still an important to know.
This is found from actinic UVA to infrared. UVA is 400-550nm of which 465-485 has the highest PAR of the blue-actinic range) which is the absorption bandwidth of chlorophylls a, c², and peridinin (the light-harvesting carotenoid, a pigment related to chlorophyll).
Near Infrared is 620-700nm which is the red absorption bandwidth of chlorophylls a and c².
Please see this article for more on the subject of PAR:
Aquarium Lighting Facts & Information; PAR
Zooxanthellae are single-celled plants that live in the tissues of animals such as corals, clams, anemones, & nudibranchs.
PUR (AKA: “USEFUL LIGHT ENERGY”) stands for Photosynthetically Useable Radiation.
PUR differs from PAR as the basic definition of PAR is ANY light energy in a specific frequency range.
PUR is the USABLE light energy portion of PAR, as well different photosynthetic species will have a different PUR range to which they respond, to which research is still behind as per exact wavelengths for many of these species.
It is important to note that an LED (or any light) can test well for PAR using a PAR meter, but still have poor “Useful Light Energy” (PUR)!!
The Picture to the left is a spectrograph with high PAR Values and high PUR percentages, from a 2012 Cree XR-E 14000k emitter
If using Apogee MQ-200 PAR Meter or similar to test PAR value you can get similar µMol•m²•sec numbers from one LED to another.
A PAR meter can sense and report light (‘photons’ or ‘quanta’) that are responsible for promoting photosynthesis which are the wavelengths that are between 400nm and 700nm.
However, if one of these lights produces energy that peaks at 450nm (the blue spectrum); while another light peaks at 590nm (yellow spectrum); your reading comparison is not all that accurate since the PAR Meter reading will be similar, yet the light producing the exacting 450nm bandwidth is clearly the better light to use, which is where a PAR meter is often over rated!.
For zooxanthellae in your coral’s tissue, the light peaking at 450nm will have greater PUR than the light that peaks at 590nm, although the PAR mmol readings are the same.
Similar can be stated about relying on PAR only for a planted freshwater aquarium, especially since many fluorescent lights can be heavy on the yellow/green spectrums which a PAR meter does not differentiate. This is also a problem with many LEDs that rely on “cool white” emitters, which unfortunately many of even the pricey LED fixtures utilize these less than desirable emitters!
For this reason LED fixtures such as the EcoTech Radion which utilize cool white emitters might have an excellent PAR value, it is going to fall short of others that utilize better daylight emitters in the more important PUR.
Based on known data as per Cynobacteria alone, and despite the lack of knowledge of certain particular corals or freshwater plant needs, we do know enough that PUR should be your major consideration.
To set PUR aside, as some arguments have chosen to do, is dishonestly ignoring known facts about lighting and its effects on zooxanthellae, plants, to even humans!
See Cynobacteria; Aquarium Answers
The problem with relying solely on a PAR reading is this does not accurately reflect “useful light energy” output, as well there is more than one way to mix light “colors” (wave lengths) yet still maintain the desired PAR and other popular ‘selling’ parameters (kelvin, etc.); these mixes of colors (often by adjustable LED emitters) are rarely optimum for PUR/Useful Light Energy.
Please read this article which displays emitter spectrographs by simply using a digital camera: PUR versus PUR
In fact as per the gimmick of adjustable LED emitters; Spectral output only holds true when the emitters are run at the operating voltage and current that they were designed for. As soon as that simple voltage rheostat is used (“control technology”) or RGB is altered, the spectral output changes thus lowering PUR.
I should also note, that based on observations by many TRUE aquarium maintenance professionals (not the Hollywood types), even a Spectrograph is not always a reliable source of exact “useful light energy” output as even when spectrographs have displayed similar charts, the results were different.
This may in part be due to the amount of energy actually delivered due to LED circuitry and driver design within each light band.
This is where you as a prospective buyer are somewhat dependant upon manufacturer claims, since wave lengths of many LED emitters (diodes) are closely guarded trade secrets.
What we can and do know is results and observations such as “LED Light Comparisons, Tests with Metal Halide.
Unfortunately the vast majority of LED Aquarium Lights flooding the market use lower quality OR older generation LED emitters that may require up to 4-5 times the wattage; such as the Boost LED or Blue Moon/TaoTronics LED. These are one in the same LED from the same Chinese manufacturer.
These may produce similar results in PAR, but NOT PUR as the better patented emitters such as the exclusive CRee & Osram Olson emitters used by Tropic Marine Centre’s AquaRay LED or the Orphek LED.
Finally as per “Useful Light Energy” (PUR), I will address a comment that attempted to insist that there is little difference in emitters between those use by TMC, Orphek and other high end LEDs using patented emitters and those used by Marineland and others using “off the shelf” emitters.
To make such a rash comment ignores the expense of development and technology of the emitter, as well as drivers and circuitry running the emitters. This displays about much sense as comparing a processor running a computer circa 1995 as a processor running a 2013 computer.
For those who believe this type of BS or want to make such comments, go ahead and hang multiple LED flashlights you can purchase at Walmart for $5 over your aquarium and see how well your Reef inhabitants or freshwater plants thrive!!
Cree is recognized as the leader in LED emitter technology and development; and even even within specific emitter bins such as the well known XR-E emitter, these emitters are constantly upgraded with patents to these upgrades.
As an example (again using the XR-E), the XR-E emitter bin utilized two years ago is not the same patented XR-E purchased today. The newest emitter emitter “updates” are kept exclusive by contract so one cannot purchase a Chinese LED fixture such as the popular E.Shine advertising an XP-G, XP-E, XR-E, etc. and expect the exact same emitter as one from a fixture that has exclusive rights to the newest developments (including the newer yet XT-E, XB-D, & ML-E emitters).
Compare this to a Chevrolet Impala; You would not and cannot expect an Impala from 2002 to be the same Impala from 2013, yet based on comments I read in many forums (especially Reef Central which seems to love to personally attack a friend’s blog), many seem to think just this.
As a final thought here, keep in mind that a high end LED Light fixture is an electronic piece of equipment that is in part only as good as its drivers and circuitry which is also why care must be given in the installation to protect against humidity or moisture damage.
Other LED Considerations/Rumors
I look at areas where fiction & facts often get obscured either by poorly worded reviews, very often inaccurate forum posts, and manufacturer claims.
- Drivers/Circuitry: What an emitter diode produces depends entirely on the power being received, which depends entirely on power supply and drivers! The results of a poor driver is an unreliable PUR which is the sad fact of many LED fixtures!!
The FACTS are most LED fixtures contain mediocre internal electronics essential for cost savings (you get what you pay for)
- First, many confuse the importance of dimming LEDs for sunrise and sunset. Having dimeable features does not make an LED bad (as some claim), but neither does this feature make a LED better as others claim.
It is also noteworthy that very few LED Fixtures use “pulse width modulation” rather most utilize “current reduction” which is inferior for retaining light spectrum quality accross all emitters!!
The bottom line is this feature is for the aquarium keepers benefit, so if you like this feature great. However if not fine too, but do not let this feature make you purchase a lessor LED if the better LED Fixture does not have this feature.
- CRI, I already addressed this earlier, so I will only add that this again is primarily for your benefit as an aquarium keeper, not your corals, etc.
- Moon Lighting; Moonlight is not Blue, so do not purchase a LED fixture for this reason only (meaning one LED fixture provides a blue moonlite phase while brand 2 has a dimmed full spectrum phase)
Be careful of purchasing brands such as the MarineLand Single/Double Bright, Ecoxotic, Maxspect, and many others as many of these lights simply do not have the best emitters as per PUR or in one companies case, infringe on patents.
For example the Ecoxotic depends upon (12) 1 Watt LED low end technology emitters versus (5) 2.4 watt very exacting wave length emitters for the TMC AquaBeam 500/600 (the 8000k white emitters use by Ecoxotic are not nearly as exacting as the patented & exclusive CRee 14,000k emitters used by the TMC AquaBeam/AquaRay); the result is although the Ecoxotic may cost 40% less, your useful energy (aka PUR) is less than 1/3 that of the TMC AquaBeam 500/600s.
Is this really bargain?
Unique Features; Lightning Storms
Another unique feature that some high end LED Aquarium Lights can perform is simulated lighting storms.
With the TMC Storm Feature and Multi Power Controller, an aquarium keeper can simulate lightning storms via an internal program that will last 30 minutes.
This feature when utilized immediately after a water change is a proven way to stimulate many Tropical Freshwater Fish and certain marine fish species to breed.
When the most important factors are considered, which this article only gives a brief ‘overview’ of (an in depth reading of Aquarium Lighting; Facts & Information is a must), the truly high end LED Aquarium Lights, of which there are currently just a few requiring only .6 (maybe .8) watt per gallon for high light freshwater planted aquariums and just .8 (maybe 1) watt per gallon for most Reef Aquariums. Of coarse this is a simplification and depth, specimen placement, etc. are also considerations.
For “FISH ONLY” of very basic planted or FOWLR marine tanks, only 1/3 to 1/2 the above watts per gallon are required.
Please note that there are many other variables such as specimen placement, tank depth, light placement that can increase or decrease these suggested wattages; Ex: a shallow tank (such as only 12 inches deep) that might be large in volume will require lower wattages of “high end” LED light energy.
These watts per gallons aquarium lighting requirements must be compared apples to apples as these watts requirements do not apply to most Aquarium LEDs as most are just cheap Chinese imitations utilizing older emitter bins without proper drivers/circuitry.
If you are still considering one of these LED knock-offs (that use “off the shelf emitters”), realize the most important light measurement is “Useful Light Energy” or PUR and although many lighting professionals recommend the use of PAR Meters as a measurement of any aquarium lighting fixture, in the end this is far from 100% accurate, especially when one compares the best emitter bins to many of the older emitter bins used by the cheaper Chinese or similar LED light fixtures.
Often the “cheap” LEDs produce considerably more useless green/yellow light and are bottom heavy in the Blue Spectrum. It is also noteworthy that a couple of these low price LED makers from China are also using stolen technology emitters and pending lawsuits will likely result in these manufacturers not being around long term for any real customer support.
Another company keeps coming out with awesome controller “bells and whistles”, yet continues to use “off the shelf” cool white, red, and green emitters. While these controller features are certainly impressive, when one does some honest homework, it still comes down to “useful light energy” and these emitters are clearly not the best for this.
That said, do not buy ANY LED for controller features, but for light energy produced. This includes TMC for their “storm feature”, which although it is cool and somewhat useful for some advanced aquarium keepers, the ONLY real reason to spend the amount of money an LED fixture costs is for LIGHT. So why not purchase your LED for actual lighting to keep your freshwater plants or coral reefs???
So consider whether your so-called “deal” of a LED Light is really a deal at all or look at it this way: would you use multiple LED Flashlights you can purchase at Home Depot or similar to light your Reef or planted Aquarium? Although this analogy may seem a bit exaggerated, it is still a reasonable analogy when one considers current technology advances and the costs of developing these advances.
In other words some of the cheap panels or ready to fit LED Hoods (such as those in 36″ lengths) are not much better than placing multiple LED flashlights over your aquarium when it comes to PUR and other essential elements of aquarium lighting.
In the next section I provide actual LED recommendations based on the TMC AquaRay line of Aquarium Fixtures.
Some jaded persons may think I work for TMC; well I do not; I simply have found their LED lights the most assessable, with the most variable applications, with the among the best science and recommendations from my aquarium service professional friends to back them up, along with excellent customer service when problems did arise once (at least where I have purchased my LEDs), and finally with fair pricing when I consider that these are very high end “Cutting Edge Technology” aquarium light fixtures.
I will also state that my friends who maintain and design aquariums professionally primarily use this line of LEDs (based on results), which their input and research is my primary reason for this article and use.
Here is a very basic RSM 250, 65 gallon Aquarium with AquaBeam Reef White LEDs YouTube Video”
YouTube Video; RSM 250 with AquaRay 600 Reef White
TMC AQUARAY RECOMMENDATIONS
This is where I have generally purchased My LED Lights from:
LED AQUARIUM LIGHTS, LIGHTING
First understand the differences between the emitters and drivers used:
*XR-E; in its most updated form (2012 as per my latest update), is the most depth penetrating emitter bin by Cree with generally good results up to 30 inches (depending upon the lens used).
*XP-E and XP-G emitters are a newer original design emitter, although it too has had been updated from its original. This emitter design at its raw core is NOT as good at depth penetration past 20 inches; However the actual light energy as expressed over a horizontal plane is higher.
And the Newest emitters:
*The Cree XT-E, XB-D, & ML-E, along with the Osram Olson “NP full spectrum Blue” (“Nature Perfect”) emitters are the newest yet.
The Osram Olson ‘NP full spectrum Blue’ is an emitter specifically designed for Aquarium Reef use in its PUR output.
The new Cree patented emitters promise to be a much less voltage sensitive emitter, allowing got better adaptation to the harsh aquatic environment.
In the blue spectrum, the ML-E Blue is generally used as a focused (lensed) emitter & therefore a deeper penetrating, High Kelvin 465-485nm “royal blue”.
The ML-E Blue can compliment other LED lights of 14,000 or less.
The new patented XT-E is used in the Fiji Blue are 420-465 nm, this emitter enhances the fluorescence of the corals. These are unlensed, and therefore are not quite as deep in penetrating as the ML-E blue, despite there lower kelvin.
Should you decide on the high end TMC AquaRay Lights, here are some considerations among the LED fixtures TMC offers;
*AquaBeam 600: Each 600 Fixture has a 24 x 11 inch light spread that penetrates well to 20 inches, good to 24 inches and fair to 30 inches (not recommended past 30 inches).
In deeper tanks such as though between 22-30 inches I recommend the #600s to add more light spread to compliment the more focused Reef White or Marine White 1000 Ultras.
*The GroBeam 600 is suggested for planted and most freshwater applications.
*The Marine White 600 is best for fish only marine applications and blended with Marine or Reef Blue as well as any actinic T5 or similar lights already present. As well, the Marine White (in particular the 1000 Ultra) is an excellent compliment to the GroBeam in planted freshwater aquariums over 24 inches in depth (generally in a 3 GroBeam to 1 Marine White configuration).
*The Reef White (18K) is generally the best overall Reef LED in the 600 strips
*The Marine Blue (20K) is a good mix with other lower kelvin daylight bulbs or for deeper tanks (often in combination with Reef White)
*The Reef Blue is NOT a complete light for proper/full PAR/PUR in photosynthetic invertebrates, so this LED is meant as a compliment to other daylight LEDs or other daylight lamps such as a T2 or T5 daylight. The Reef Blue (as well as the Marine Blue) is also useful in tanks up to 30 inches for to compliment lower kelvin daylight in light penetration.
*TMC Mini 400 & 500:
*Each Mini 400 has a 15 x 15 inch light spread that penetrates well to 18 inches in freshwater.
Excellent for high light planted Nano aquariums (15 gallons or less, including small hex aquariums), as well the unique shimmer effect looks very nice with this newest offering by TMC
*Each Mini 500 has a 15 x 15 inch light spread that penetrates well to 18 inches in saltwater
Similar to the 400; excellent for Reef Nano aquariums (15 gallons or less, including small hex aquariums) for all but the most demanding reef life (which further test may yet prove OK for as well)
The Mini 500 includes 4 lensed CRee patented XP-E 10,000K and one unlensed Blue CRee XP-E. with a unique switch to control off & on, blue only, or all.
The Picture shows a Mini 400 mounted using a MountaRay bracket and head on view of the Mini 500 Reef, Marine Aquarium LED.
*GroBeam 1500: Each GroBeam 1500 has a 24 x 24 inch light spread that penetrates well to 24 inches in freshwater (A Marine White would make a good compliment for tanks 24-30″ in depth in a 3 GroBeam to 1 Marine White configuration).
This is their best planted aquarium light BAR NONE with the most useful energy per square inch within the footprint!
Do not believe a certain unscrupulous live plant aquarium retailer that bad mouths these LED fixtures and has likely never used these lights.
As well, this person continues to push older technology inferior T5 lights; the FACTS are the GroBeam 1500 (& 600) is THE BEST freshwater planted aquarium light, period with the science to back it up!!
This light has been proven by so many to not only grow freshwater plants, but make plants thrive and explode in growth, their are many articles and aquarium forums documenting this!
*Colour Plus 1000/1500: This is an excellent light for making fish, plant, and other colors “pop”
Excellent for low to medium planted aquariums by itself and as a supplement to the GroBeam or other Reef LEDs for high light planted freshwater or advanced reef tanks.
Similar to the EcoTech Radion, except with less blue, which makes it a better choice for freshwater, although by itself a lower choice for reef tanks. HOWEVER this light exceeds the EcoTech Radion in that it utilizes newer generation XG emitters and more importantly does NOT use “cool white” as does the EcoTech, rather it utilizes 9000K Daylight emitters.
*Reef White and Marine White 1000: Each AquaBeam 1000 Ultra has a 16 x 16 inch light spread that penetrates well to 30 inches in saltwater (& freshwater for certain applications). The Reef White is the best LED for deeper applications or to compliment others other very delicate reef specimens such as Maxima Clams. The Marine White is also a good compliment (not the only LED) in planted freshwater tanks over 24 inches in depth. As well the Marine White & Reef White 1000 is a good compliment to Marine Blue or Reef Blue 600s in deeper tanks.
*AquaBeam 1500 Ultima; Ocean Blue 20k: Each Ocean Blue NP Ultima 1500 Tile (20K) has a 24 x 24 inch light spread that penetrates well to 20 and maybe 24 inches in saltwater (& some freshwater applications).
This new LED fixture contains these emitters; (2) x Cree Patented XT-E Fiji Blue, (4) x Cree Patented XT-E Ocean White, and (4) x Osram Olson NP Blue.
Best results with these fixtures is for specimen placement under 15 inches (22 inches max), however the NP Ocean Blue 1500 can be mixed with the Ultra 1000 LED fixture for tanks much over 22 inches in specimen light placement
The Ocean Blue NP 1500 is excellent for use in most shallow Coral Frag Tanks, since these are unlensed emitters, resulting more light spread but less depth penetration
As with ANY aquarium light, placement of your freshwater plants, sps corals, maxima clams, etc. can make a major difference in the amount or number of light fixtures required.
I know of many who have kept reef specimens and aquatic plants with half the recommendations I have made here. In these aquariums the plants or corals were placed directly under the lights with the entire tank simply not 100% lit.
An example is a friend with just one GroBeam #500 in a 40 gallon aquarium with live plants that are thriving and growing (this tank is actually well lit with just one GroBeam, but the plants are directly under the 24 x 11 inch footprint of lighting).