Noob: LED lighting question

[Loadedgunz]

Hello guys,
I'm just getting into the reefing hobby, but I wanna make sure I'm fully prepared before diving into it. As I'm researching about all aspects of reefing, I seem to understand everything I dig into, except for lighting. I understand that there are compact fluorescent, Metal Halides, and LED's as options for lighting. And I also understand that LED's seem to be the most popular option these days. However, what I don't understand, and what my elongated question is: why are LED's more commonly used as hybrids with T5? If they're such amazing lights that can pretty much mimic and distribute any color in the light spectrum, why use additional lights? What can you NOT grow with them alone?

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[Entacmaea]

Hey there - welcome to the addiction! There are as many opinions as answers to your question - some will say LED's can't grow some corals as well, whereas some will say LED's can grow anything. As LED's increase their track record and length of time in the hobby, I think eventually there will be little argument that they can grow anything any other strong lighting can. Some still swear by Metal Halide to color and grow SPS corals the best, but there are plenty of tanks and examples that are getting great results from just LED's. Some people supplement LEDs with T5s to try to get the best of both worlds - efficient point source and adjustable spectrum from LEDs, and diffuse proven lighting from the T5, often to decrease shading effects of some LED fixtures. There are plenty of examples of success with any lighting scenario (livestock dependent of course) lots of t5 bulbs alone can grow anything, just metal halide can grow anything, just LED, etc. Some lighting has other advantages - LEDs being running cost (save on electricity) and control-ability. In my opinion, the quality LED fixtures can grown anything any other lighting set up can grow, nowadays... Hope that helps!

[Dj Anarkee]

A little back story... I was reefing about twenty years ago and much has changed since then, so I'm back in research mode again.

Here is my take away from the research I've been doing lately:

T5s are tried and true and provide great, diffused, even lighting, and people feel safe with them.

LEDs are newer technology. Though, it seems they have been refined in the past ~5 years and have been dialed in well for growing anything.

People are slow to change. I didn't do the same wet/dry sump everyone was doing back in the day. I was skimming and using carbon. People thought I was nuts, but it worked for me. Now that is pretty much the norm from what I can tell (with the addition of refugiums, which I think is a great addition as well).

Bottom line is I think some of the mid to higher level LEDs are more than capable without the T5s (not to mention the lower operating cost). I have my eyes set on the SBreef LEDs right now based on other user recommendations and price range.

The take away for you should be:

Many people have been in this hobby for many years. There are a million different ways to succeed and just as many ways to fail. Do your research. Figure out what you want to keep. For me it seems the SB lights will do well for me. When I pull the trigger and get a new tank up I'll let you know how it goes.

Best of luck and I hope this helped!

[Ron Reefman]

First a couple of points. I've been in the hobby 12 years now. I've had tanks with PC fluorescents, t5 fluorescents, MH, MH & t5, and now leds (over all 4 tanks).

Your questions:
1) Why are LED's more commonly used as hybrids with T5?

I wouldn't say leds are more commonly used with t5's as hybrids yet, but it's a newer trend for sure.

2) If they're such amazing lights that can pretty much mimic and distribute any color in the light spectrum, why use additional lights?

Because leds use lenses that make the light very focused. Think quality flashlights, not quite lasar like, but much more focused than any other light we use. And that light is coming straight down from above. They create very deep shadows under rock or coral ledges. Some led fixtures have just a couple of red and green leds which can make red and/or green edges to the shadows (commonly called 'disco effect'). To some that is totally unacceptable and to others (like me) it's just a fact of life.

By adding a t5 or 2 in front of and behind the leds you now have light that is being cast out in at least 180 degrees and/or bounced down by reflectors that again, scatter the light (the opposite of 'focused'). The t5 helps reduce the shadows and reduce or eliminate the disco effect.

3) What can you NOT grow with them alone?

There is nothing that can't be grown under led fixtures. However, due to the focused light. some corals that branch and still remain quite 'dense' as they grow, like frogspawn, hammers, duncans, birdsnest, and pocillopora, will spread as the grow vertical and thus shade the older growth below. Without the light, the lower growth suffers and can die. I had a tri-color pocillophora that was 12" in diameter at the top and looked beautiful. But it was also 12" tall and the bottom 8' to 10" were just dead skeleton because it didn't get light.

I hope that helps?

[Loadedgunz]

I really appreciate the feedback and the help folks! I really love the idea of going with only LED's since I want to be as energy efficient as possible. What would be the best way to eliminate or reduce the shadowing caused by LED's besides combining other forms of light with it? Are there any brands or setups I should be shopping for such as specific spacing, reflectors, etc.? Thank you again.

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[Wazzel]

I really appreciate the feedback and the help folks! I really love the idea of going with only LED's since I want to be as energy efficient as possible. What would be the best way to eliminate or reduce the shadowing caused by LED's besides combining other forms of light with it? Are there any brands or setups I should be shopping for such as specific spacing, reflectors, etc.? Thank you again.

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Figure you will need 1.5 to 2 times the number of fixture the manufacturers recommend. Something like the AI hydras and ETM radions cover about 18" in the short axis and 24" in the long axis. D2mini runs 3 ETM radions on his 4 ft tank. I run 4 AI Hydra52's on mine. 2 of either were not going to cut it.