Mr. Saltwater Tank

Terrible Advice Tuesdays (T.A.Tues): LEDs a viable lighting choice for your saltwater tank? Yeah Right!

Terrible Advice Tuesdays: LEDs won’t grow corals.

The rest of the story: I can’t believe I’m still hearing this idea passed around especially considering mounting evidence of LEDs successfully growing coral. I can personally say I’ve got clients growing corals (even hard corals) under several different name-brand and D.I.Y. LED fixtures. Since 2011, I’ve had only LED fixtures over my tanks with good results. Jump on any forum and you’ll find plenty of threads of corals growing, and growing well under LEDs.

For those of you liking more concrete evidence, scientific experiments have been done to test for corals growing under LEDs with good results.

Of course, any topic, if you go looking hard enough for the evidence you are after – in this case corals not growing under LEDs- you’ll find it. Remember that the outliers on a bell curve are just that – outliers. They should not be used to make a decision where there is plenty of contradictory data.

Are LEDs still a relatively new lighting type for saltwater tank? Absolutely. There is still lots to learn about LEDs and their application in a saltwater tank. Contrast this with older lighting types such as T5 and metal halide where we’ve had 20+ years to test, tweak and perfect the lighting type for our tanks.

LEDs are a suitable option for lighting your saltwater tank and the future is only looking brighter for them. Don’t let the few people who have had bad experiences cloud your vision.


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Comments for this article (43)

  • Burelle says:

    The only critic I have about leds is that we still don’t really know how much to use. With MH it’s easy, T5 and T8 as weel because we’ve seen first hand what they can do. But as you say, leds are new and as such should be used and tested. It’s the only way to know. For my reef tank (62cm*45cm*62cm high) I had à 150w MH, I switched to leds, 60w to be exact. People told me to go for 120w or 160w, but I contacted directlty the maker and he said the 60w was more than enough to pack a punch even at the bottom. The point is not to only listen to user on forum cause they don’t really know either, but to ask directly the maker. Then it’s trail and error. The economical side of the argument is off base, the lighting itself may consume less but the balast won’t and the price difference will not show for about 5 years, juste about the time that you have to change the lighting. However you will save money on cooling the water….

  • Good day,

    I tried cree led lights last 3 months. dark color easy hard corals growing well. but for other coral not good. So now ı am planning to change T5 again.

    Cree led lights very good for all other corals but not hard corals.

    best regards
    capt.ilyas OKTEN

  • rich says:


  • rich…I hope you aren’t driving a car or using a smart phone either as those companies are making good money, and the products are continuously being improved.

  • Leighton says:

    Ilyas….. sorry but I could not agree less. I have been growing sps under leds (cheap chinese ones at that) for the last 18 months. Bali slimers, encrusting and plating monti’s, tricolour acro’s and digitata’s all grow fast, with good colouration. The only thing that wont grow is Millepora. My rhodactis Inchoata have however melted. But yes stonies will grow and grow well under led.

  • Joel says:

    I have heard from a former representetive that worked for a big name dealer who was offered a big chunk of $to take his T5 + MH fixture off his gorgeous reef and put their name brand LED’s on it for photo op to sell these things. No one else kept LED’s over thier tanks that were in the co. He refused this offer. Anyway he has gone on to inform us that LEDs fade out and need replacing more frequently than people are led (lol) to believe.

  • Chad says:

    I’m relatively new to the game, in about three weeks I’ll have had my saltwater aquarium for 1 year. I upgrade so now I have a 125-gallon. I started out with a 48inch LED from Marineland. I had to get an extension because my tank is 6 feet long, but I still use LEDs on the whole tank, now I have a 48inch and a 24 inch.

    I have experienced a couple of corals that don’t do as well in my tank. But I have more corals that do just fine in my tank without issue. It is a learning process because I’m still seeing what works well in my tank. However, it might not even be due to the lighting.

    The other good things, I have a 7-year guarantee on these babies. If one bulb goes out, it gets replaced for me for free. I don’t have to change bulbs every few months, or keep track of bulbs to replace. With that, I don’t have to spend money on bulbs, I can spend it on fish and corals.

    I’ll be interested to see what kind of research there is in 10 years and I’m sure I’ll look back and say “dang, no wonder that coral didn’t do as well” or something to that effect. But just like fish, I’d say that some corals just don’t work in your particular tank and that’s how it’ll go.

    If you ask 10 aquarists for their point of view, you’ll get 12 opinions back.

  • JasPR says:

    Life is about change! But the techie generation of today absolutely believes in constant change!! And therein lies the marketing scam potential! There IS an evolutionary highway to all things. But there are also many many exits that lead to dead ends. NOT all LEDs are ‘good’ and not all old style techniques are ‘bad’. Rather, in a world of grey ( as opposed to black or white reviews) we can expect a kind of dance or upwardly climbing ratchet style of advancement.
    In the end, mother nature is not changing photosynthetic processes. It is the same now as it has been for thousands and thousands of years. What triggers the process, and whether one technique is .00005 better than another, doesn’t bother ‘her’ in the least. If you build it, she will cooperate * just try and stop her! 🙂
    For what its worth, JasPR

  • Joel says:

    Also why are there Gen 2 and so forth remakes. Ask these vendors what they light their reef tank with. I am just in search of the truth Mark.

  • Danspyvey says:

    I have the same issue as Burelle. How many watts? What lighting footprint? Which colors? It’s all to new for me. I have 2 frag tanks both 24x24x12 and bought two of the Chinese lights and my corals have just never done the same as under metal halides. Unfortunately, I just can’t afford the 800 lights, and never will. I’m at a point where I’m thinking of switching back until there is a more “rule of thumb.” I’m open to any suggestions. Thanks

  • Paul W says:

    Mark, I’m wondering if you’ve had luck with your LPS corals, particularly Acans under LEDs. I’ve seen a video from Mike Paletta suggesting that in a recent LED experiment he undertook on a newly set-up 75g, he got less than desirable growth on his acans from LEDs, in fact, he said the tissue was pulling away from the skeleton. He couldn’t definitively state that the LEDs were the issue, so I’m wondering about your experience.

  • Anh Dao says:

    Got 3 radion pro over my 150 and all the SPS grow really fast. Only need 65% at 20k. Colors look great also. So led does work I guess.

  • Patrick says:

    I have had my ecotechs for almost a year now. I have had very little to no growth in my tank. Around 4 months ago you said you kept your brightness at 20% I changed that but still not a lot of growth. I used the radiant color settings on the radion but I don’t think that setting gives enough light. I finally installed some dosing pumps. If I don’t start seeing better results I will gave to trade in my ecotechs for and ati light fixture. I don’t want too but the LEDs are just not growing anything.

  • Jim says:

    My 150XH has been set up for close to a year now. I have never run anything other than LED’s. I built my own fixtures with all Cree LED’s from Rapid. I have 4 units with 24 LED’s each and a custom controller with channels for Royal Blue, Mixed Whites, UV & Red. IMO the issue with my LED’s is the user (me). At first when I built them I’d see a well-lit MH tank and like the look of it. I’d go home and adjust my LED’s to look the same and guess what, It’s too much light for my corals. I have Milli’s, Monti’s, Stylo’s, Euphyllia’s and a bunch of Acro’s including Ice Fire Echinata, Strawberry Shortcake, Caroliniana, Cali Tort and Blue Monster. All of them do extremely well under my LED’s with great growth & polyp extension once I figured out how to properly set my lights. I’d get a frag that was at the top of a tank from someone that was running a couple 400w MH’s and place that frag at the top of my tank thinking it could handle/needed the light. Well it can’t and I end up moving it down till I find the right level for that piece of coral. I wasn’t always getting the colors I wanted from my corals so over the last couple months I have been reducing the output of my lights overall and am seeing brighter colors as a result. Again supporting that what we think we see with LED’s is not always what the corals need to thrive. My tank is by no means dimly lit, but It’s just not as bright as a tank with a couple 400w Metal Halides. I recently built a fixture for a 40 breeder that I set up as a frag tank. In that one I am using way less LED’s.

  • Dave says:

    Its always incredibly funny to hear comment like this. People will search and buy the absolute cheapest version of a fixture or piece of equipment and then write horrible comments about how poorly it performed. If folks spent half the time researching things before they try them we’d all be spared their horrible stories of failure. Remember before all of these technological break throughs people grew coral and raised fish with them. It was hard but done. then there are those with every piece of equipment known to man and their tanks crash… That’s why I love reading your reviews, guides and video’s You can never share enough data…
    Thanks Mark

  • clynn wilkinson says:

    vivid aquariums is doing an experiment. left side of their display tank is M.H right side is all l.e.d. they have had them that way for at least year. here is a link.

  • Salvatore Abbate says:

    I do agree with Mark that LED’s are a good option and they will only be getting better. There are a lot of pros that go with purchasing and owning LED’s. As technology increases, the price will continue to go down making it an even more viable option.

    For me personally, I am using MH lights on my current system and purchased four 400w MH for my current 300 Gallon builld. I wanted to go with LED’s because I love the sunrise, sunset, thunderstorms etc.. but when I took a trip down to Los Angeles to Vivid Aquariums and sat in front of the 900 Gallon tank that is half lit by Radion LED’s and the other have by MH the choice was easy for me.

    The MH side of the tank looked much brighter, the corals more crisp etc.. When looking at the LED side it looked dull in comparsion.

    The best way to describe what it was like, is if you ever go to a TV store and look at all the TV’s hanging on the wall and see them side by side, you can really tell the difference between the real expensive high end TV’s and the cheaper ones. The high end TV colors are much more vibrant, the whites are really white, the blacks really black etc.. However, if you purchase the lower end TV and bring it home, it looks great in your home since it is not next to any other TV’s. That is exactly what is was like standing in front of the Vivid Aquariums’s 900 Gallon tank.

    There are some amazing SPS tanks under LED’s out there, but most of those tanks have some very advanced reef tank owners that are tweeking the lights, and really know how to run a reef tank.

    For those fish / coral stores that are selling high end corals, you will see that the SPS corals are under MH lights and the LPS are under LED’s.

    In the end, LED’s are coming along very well, and yes I am happy to see Gen 2’s coming out, because it shows that the technology is getting better and it is better for the reefing community as well.

  • James says:

    I think it would be a great idea if you could go visit a few of the major led brands and pick their minds and point them out in a show and have it on your am quick tips or just a video in between.

  • Chaz D says:

    The best led tanks I’ve seen were supplemented with T5’s. Most commercial fixtures don’t address the shadowing leds cause…hard to get on board until they address this problem with angled fixtures. The sun isn’t directly overhead all day long.

  • Glenn W says:

    I’ve exclusively used Ecoxotic stunned strips on 3 diffrent tanks and guess what softies, sps, zoas all growing fast and huge. The one thing I did notice, with my ph at 7.9 I didn’t get as much growth of my SPS until I got it to 8.4, they did grow but really took off once the ph was near 8.4 and Ca was at 500 Everything else doesn’t care, just the SPS. After a couple of years under LED’s I’ve saved a bunch of money and never had to replace anything. Great growth (for SPS comes more from chemistry, an aged tank, flow more than T5s vs LEDs IMO) on everything.

  • Morgan says:

    I have made the switch to LED’s in my 30 gallon “sexy” tank, yes I do have a small group of sexy shrimp hosting in my flower anemone and a bi-color blennie, thanks to you Mark :). I am using dimmable 120w full spectrum bridgelux 3w LED’s running at 2w. The unit has a total out put of just over 4k lumens. First and foremost the LED’s sure make those colors pop. In fact I enjoy the color of the LED tank better then my PC tank and my t5/MH tank. As far as growth with the LED’s go for me is unknown. I have only had the “sexy” tank up and running for a short time now so I have not seen much growth but I am very eager to log my results in the months to come. And you don’t have to replace any blubs every 6/12 months. That alone will pay for itself in a couple of years.

  • Joseph says:

    @ Paul W

    I won’t trust anything Mike Paletta says about LED lights anymore. In that same video he says he had chemicals in the house and had huge PH issues.

    Corals dying, not looking at the issues the tank had, he rather blamed the LED’s. Lost all credibility in my books.

    Mark – agreed, you can grow corals under LED. Photons are photons, the coral couldn’t care less what emitted them. As long as you provide the right spectrum at the right strength, a coral wuld not distinguish what created it.

  • JaspR says:

    Exactly. I have a 180g in a sunroom but with no direct sun. Lots of tall trees outside so the picture windows only let in bright indirect light. The MH are almost washed away by that bright natural light. The corals love it ever see a polyp smile ? 🙂

  • Mark says:

    I would have to agree that chemistry is King! I however, would like to see some combo fixtures, LED/T5, for those of us not using a canopy. Maybe I’ll have to create my own company and design it. Happy reefing!

  • kevin says:

    Lol @ the amount of reactions.

    Anyhow. I’m using tritron pacific sun units. Before that the high power pacific sun units. Do they grow SPS corals. Heck yes. Most LPS corals even on the bottom have too much light (i run them at 75% ) Currently building down. I feel comfortable at 75%. At 100% my corals stopped growing.

    Monti’s grow like crazy anywhere . My milliopora grows really fast almost on the bottom. I got a Strawberry shortcake midway in the aquarium, growing really well. Red and greens really pop color wise. Blue is a little harder, but i can’t really blame that on the LED’s. Blue’s have always been harder for me.

  • Joseph…my sentiment exactly on the photon part.

  • Matt says:

    Sorry but it’s important to realise that without question that coral grows and grows well with good reef skills under led’s … Not ever led fixtures are born equal so do your research as you would with any part of your tank…

    As suggested… Take a look at the big forums and see what people are doing with led … the high end units are proving again and again what can be done whilst still saving energy and money! Think Radion, Vertex and Lani’s …

    If you dispute led’s as a good option then as far as I’m concerned don’t help anyone out with their reef tanks .. you’re not a forward enough thinker to be furthering the hobby and helping newbies out!

    With running costs spiralling we need every advantage… how else do we keep on buying frags 😀

  • mark f says:

    I’ve been running 800 watts of MH light on my tank for 14 years. When I first started adding sps, some lived and some didn’t. My understanding is that if you are starting a new tank with LED you’ll be fine. Some sps will thrive, others won’t but, if you have a tank and are transitioning to LED it’s not so easy and a lot of people aren’t willing to experiment with their big colonies that they have had for years.
    Also, I see specific colors pooling in the sand. So, if a coral is right under a red LED it is getting blasted by one color of light. The blended light of LED is not as pleasing to look at as LED.
    So, I won’t be switching for a while. Plus the mark-up of LED fixture cost vs. what they are charging is a little silly.
    I love advancing technology but, it has to make sense for my particular situation and at this point, it doesn’t.
    That’s not to say I wouldn’t recommend LED to someone starting a new tank or supplementing existing lighting.

  • John says:

    You sure did (poke the bear) with this topic !

  • Mark says:

    I am growing SPS, LPS and softies all under LED’s. All are growing rapidly, maintaining color, even a purple SPS is growing and keeping its color. The softies are huge, the Goniopora are gorgeous as well. What more can I say but give them a chance! Maybe for those of you without success don’t have the correct LED’s to begin with.

  • Duane says:

    Corals will grow under both LED and MH and/ or T5. Like all things, there are good brands and not so good brands for any lighting set ups. MH and/ or T5 have been around for much longer and are better understood. LED’s have improved greatly over the last few years and will continue to do so. Like Mark recommends, get a fixture that is modular and can be upgraded as new technology is available. One thing that I think that we’ll find is that the actual LED’s won’t last anywhere as long as the claims state. This just has to do with heat due to the fixture designs. Really not a concern since most will want to upgrade long before the actual LED’s fail.

  • Alex says:

    I have had good success growing SPS corals with Marineland reef capable LEDs (the newer with timer model). The only catch is I have to have 3 units to get sufficient lighting. But other lighting options were not suitable for me for various reasons.

  • Sean(Cyberseanx) says:

    Just for the record, I have been using nothing but LED’s for over a year now, Building up and down, using different amounts of light at different times of day as well as mixing actinic blue with 15-20,000K of LED light.
    I have had great results and They can easily represent different times of day giving the tank a natural feel for your swimming friends and reef critters. I used 10,000k at 10w on the outside area of the tank and 12-20,000@ 20w on the inside, A full mixed LED (60w) fixture in back and two small strips (9w x2)of mixed on the sides. seven total. They don’t take up allot of room like the T-5’s and use a lot less power, don’t fade fast and last 10 years at minimum. yes, this is a new style of lighting but I think for many reasons they will take over, and fast.. they are just to damn versatile and efficient. All of my leathers, Gorgonians and soft corrals, are huge and I have More frags than I can handle, If there is any question to how efficient..Have a good one!

  • Speedy says:

    My personal experience with LEDs is much like marks. For the past 5 years I have only run LEDs. I just recently upgraded. On my new set up I went with the new onyx fixture by I wait 6 months before adding any coral. The onyx is my first full spectrum LED vs my last were just 50/50 blue/white(which I had for 4.5 years) and I can say my corals have doubled in size since I bought them 2 to 3 weeks ago. While I must say after having this experience with full spectrum I can say that 50/50 probably wont cut for thriving corals but is a good alternative to a chiller if you want to have some corals.

  • Pierre-Yves Bouic says:

    This is a complex issue, the whole MH V LED thing could fill weeks of comment pages with pro’s & cons. I’ll say what I’ve experienced that is since recently upgrading to 2 x 120w led each with 55 bulbs of 2w @ 14k & a dimer switch, I have had mixed results. Previously using 2x 150w MH of 14k supplemented with 6x T5 . What was stressed to me was to give low level amounts of led to start the conversion process, over 2 weeks reaching 80% of the 120watts of LED. All went well, some corals are growing better like acro’s, sps, & Lps species. Cori-morphs seam to not be as large as under the previous mix of MH & T5. Their are so many options available on the market especially from China. I chose what I was told was a powerful product called Spector 120, made by Green Sun Opto-electronic co. They are almost to powerful so I mounted them higher because the panels being rectangular gave a concentrated area of light. At 2ft under water the PAR is 7000 lumens. So I’ve made my rockwork into an island under each light. The look is different to the same style of panels in MH, & the corals seam to be getting more light now than with near 700w of T5 & MH. After all it called perceived ambient radiation, so what we think is not that bright may be too bright to a coral & its needs. The biggest advantage is less heat( especially in Australia) my chiller was on all day B4, but now only 1or2 times a day max, low power usage, & not having to replace lamps or tubes are major pro’s. You must do your research & be prepared to arrange the corals at new heights. I will agree that its easier to start with new stock under LEDS than acclimating existing to do better under them. But if you start with low % of new led light it will give better results. What is much better is the actinic, the levels of light in this range are much greater than T5. Using them only gives totally new colours & brings out better shades. If you have dimmers on both main & actinic leds try to experiment with the best day V dusk levels. I give LEDS a thumbs UP.

  • JasPR says:

    I know I’m not making as valuable a contribution as some of these posts have made, but I’m like a ‘dog with a bone’ when it comes to pulling one’s head out of the statistical analysis (often seen as enlightened but just as often a case of missing the forest due to the trees!) and refocusing on THE BIG PICTURE.
    To understand any biological challenge one must first establish a range of perspective. Often that only comes with time and experience and so the learning curve for newbies tends to be long and brutal. Indeed, a learning curve that results in 80% of budding hobbyists dropping out in the first one-two years of entering the hobby. Money, busy life and disappointments coming from over the top promises of the marine hobby marketing crowd are mostly to blame I suspect. But being a big personal responsibility guy, I also see the hobbyist as being lazy or at least, not too motivated, when it comes to efforts to learn the BIG PICTURE of things. Not demonstrated here of course as evidenced by folks responding here. They are obviously advanced and/or are doing their ‘homework’– and it shows.
    So before I get too far down the rambling road, let me add this– IF you use LED white/blue or just ‘white’ actinic, you WILL notice that you encourage too much ‘wrong type’ algae growth and not enough coral thriving. IF you use old/aged MH you will see that creatures like rose anemone move towards the surface and more water flow. This tells you that BOTH intensity and spectrum influence in different ways. Perspective is experience. But I digress– JasPR

  • JasPR…so that people reading the comments don’t get the wrong information, I/none of my clients/fellow hobbyists I trust have NEVER experienced this, ” IF you use LED white/blue or just ‘white’ actinic, you WILL notice that you encourage too much ‘wrong type’ algae growth and not enough coral thriving.”

    As you know, algae grows where there is nutrients and lights, just using blue/white LEDs won’t encourage any more algae growth than using full spectrum LEDs, or similar powered MH bulbs.

  • Steve says:

    I have three 250W MH and with T5 actinics on my 125 Gallon reef. I have not yet tried LEDs. And I have to say, I really love what LED lighting is doing for the cost of operating my MHs. Their entry into the market is depressing the cost of new MH bulbs. [Obviously it does not affect operating cost – electricity and cooling]. So I love LEDs. I can now better afford to change my MH bulbs yearly. If this keeps up, the price point for making the switch from MH to LED might not come in 3-5 years. It may require 5-8 years.

  • Phil says:

    I have a question about wattage. I have a very small 14 gallon biocube and the lights that come with the biocube do indeed have to be replaced every 4-6 months. I decided to “upgrade” to a Current Orbit Marine LED fixture. Low price point, LED, but only 18 watts. Whats the rule of thumb on wattage? I’ve seen so many different rules of thumb from 5 watts per gallon to one watt per gallon.

  • Arrgh says:

    Phil, it might be best to consider the LED elements themselves rather then the total wattage.

    Suitable fixtures typically supply 2-3 watts or more, give or take, to each LED.

    That being said, small nanos (read shallow) may do just fine under fixtures such as the Orbit.

  • Cbear says:

    I decided to buy a “budget” LED “reef” fixture just to see how frogspawn would do. I bought the Current Orbit LED Marine Fixture 48 to 60″ and 46 watts. The LEDs are only .25 watts each, however each one has a 120˚ angle and they are rather close together. I wanted to see if .25 watts per LED was a fail. Well, 7 months later, my 1 polyp frogspawn is now 4 polyps. That with the light being over glass which can have algae on it at times from a cheap LED strip I use just to light up the front of the tank. The Frogspawn is about 5″ from the light. So it may also have to do with the quality of the LEDs, more so than wattage. Just my 2 cents, not that I am an expert, but I did have a successful experiment!

  • Cbear says:

    Oh, my bad… this was on a 75 gallon tank

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