The myth of LED efficiency

[+Hydro]

Timfish great answer. Mike I agree with you about the coloration too, its just like tuning off the MH in my tank and just leaving on the actinics. The colors immediately pop but there is no difference in the actual color of the coral. Now on the other hand b/c of different lighting some coral can change color over a few days or even months, this is a real change in color no matter what lighting you have it under. I have a colony of JG yellow in my tank that when I got it was yellow of course but after a couple of months its now green as grass, if I put it in someone elses tank it would be green for a short time and then turn back yellow like it should. There are reasons that the pigments change which makes them reflect different colors, I'm sure there are several reasons for that. I've never seen a JG yellow in someone elses tank that wasn't yellow, but at the same time my red planet is the richest color of red that I have seen before. I do think that lighting plays a major role in that and a perfect example is yesterday I met Bigbird and after talking we realized we had the exact same lighting, bulbs mainly (12k reeflux SE), he told me yesterday that everyone comments on his red planet b/c of the rich color that it has. Our RP look the same b/c of the lighting that we both use IMO, its too coincidental that we have the same bulbs and the same look to a coral that we see in many peoples tanks with a different color. To agree with Mike though if I let my temperatures rise on my tank or let my water quality slip my corals could be brown using the best lighting possible.

One of the local farmers uses 10k for a few weeks for growth and then switches to a 20k to get better coloration. Seems like to me the perfect setup would be 10k lighting with heavy actinic supplement. Seems like you would get the best of both worlds but I have never tried it. I used the 12k reeflux SE (single ended) since the begining b/c when I first got in to the hobby I bought some frags from Jon G and asked him...he told me that these were the best bulbs out there so that's what I use with actinic supplement. There is a hint of blue but I like them b/c it doesn't make my tank look purple which I don't like...even though the corals pop more.

[OgreMkV]

As an addition to what everyone else has said, corals (indeed all photosynthetic organisms) do best at a spectrum of about 6700K. That's the spectrum put out by the sun. Photosynthetic compounds (generally) peak around 420-460nm and around 650 and 680 nanometers.

Interestingly, the compounds that make corals glow (like we like) and much of the coloration of them are actually proteins that the coral uses to protect itself from UV radiation. The more UV, then more proteins are produced and the brighter the corals glow.

So, get the lights that make the corals look like you want them and then sufficient lights to make sure they get enough photosynthetic byproducts to thrive.

my 2/100s of a dollar

[Teresa]

So that then raises a question in my mind: Why do we use MH if their output is far above 6700k (i.e. 10k, 14k, 20k)?

[Timfish]

The tanks look better. I've both used 5k and 6.5K bulbs myself and seen other peoples tanks with lower K bulbs and because of the added green, yellow and orange light it looks much browner. A lot of corals I've seen under the lower K bulbs also turn predominately brown a process I'm inclined to think is analogous to us getting a tan (obviolsy different pigments involved though). I've never bothered to measure the light output of a 5K or 6.5K bulb but I'd guess it would put out more light than a 10K bulb which might explain in part the color shift.

I really do long for the day when I can look at my tank and think "I've got a spot right there that needs a coral" and put a meter to check the light and it say's I've got this much light at 420nm, this much at 430nm . . . this much at 680nm. I can then get online and check my local club's website and database and look up to see what corals would do well under the light I have and if I PM Teresa she's got this coral that will keep these colors or Mike's got this coral that will keep this shade. Or if I see a coral that's got an interesting contrasting color scheme I can measure the light it's getting and go home and tweek my LEDs to give me the right spectrum in this spot I just cleared out.

Maybe next year

[OgreMkV]

So that then raises a question in my mind: Why do we use MH if their output is far above 6700k (i.e. 10k, 14k, 20k)?

Because it makes them look pretty. And that's pretty much it.

[Teresa]

lol - Thanks for all the input everyone!

[OgreMkV]

Let me add a few more comments here. I've been running LEDs for almost 6 months now. Before I had a 96W PC bulb (dual 10k/actinic), now, I've 160Ws of LEDs lamps (60W 18k, 60W 10k, 40W actinic). I've also decreased my photo period from 10 hours to just less than 8 hours per day.

1) Over the summer the tank temperature has been 2-3 degrees cooler than last summer. Notably, we're running the AC less this summer (thermostat set to 80 during the day rather than 78. Last year, I struggled to keep the tank temp at 80-81F. Over the last three months, I haven't seen the tank temp above 78F.

2) Before LED, I had one SPS (birdsnest) that didn't do very much for 6 months (maybe doubled in size). After LED, the birdnest has increased to 5-6 times what it was prior to LEDs and I've added 3 more SPS with a fourth coming tomorrow.

I respect the information that hydro is presenting, but from personal experience, I can say the LEDs do the job. Plus I have the option of just running part of my lights, not the whole thing.

P.S. I'll be happy to show how mine work tomorrow to those who come to the ARC meeting at my place.

Edited August 21, 2010 by OgreMkV

[Dena]

OgreKV, I've got the G2 light...110W. What exactly is your lighting schedule? I'm thinking mine may be too long because I couldn't get the cyano to stop. I believe the blue turn on around 11a.m., white (don't have the 30W bulbs) turn on at noon, white off at 8p.m. and blue off at 9p.m. Last night I did replace the sand with a new bag of Hawaiian Black (and do a major water change) and put back only a few rocks, a couple softies and the fish and inverts. No cyano today...so I'm thinking it was partly the sand...it was from a sump and pretty dirty.

I need to move my Solana contents which does have SPS and a nice RBTA into the tank with the G2. They are currently under and LED fixture my hubby built that has a mixture of cree bulbs, 12 blue and 12 white bulbs at 3.7W's each. I'm thinking G2 will still do well for the corals as I have another RBTA in this tank recovering and it's coloring back up quickly. What are your thoughts? FYI...I got this light after I saw yours LOL...got in on a group buy for $400 including shipping.

Also do you use the mounting rack or did you suspend it and if so how high do you have it from the water? I don't know why, but I'm worried not suspending will put it too close to the corals and stress them out. I had a chalice on the side before, somewhat shaded and it started to bleach.

As far as my opinion on LED's...I really like the color. There is heat, but it's directed up. I actually have a heater on my Solana...usually stays about 78, but never goes above what the temp in the house is (80 when we are at work).

[OgreMkV]

OgreKV, I've got the G2 light...110W. What exactly is your lighting schedule? I'm thinking mine may be too long because I couldn't get the cyano to stop. I believe the blue turn on around 11a.m., white (don't have the 30W bulbs) turn on at noon, white off at 8p.m. and blue off at 9p.m. Last night I did replace the sand with a new bag of Hawaiian Black (and do a major water change) and put back only a few rocks, a couple softies and the fish and inverts. No cyano today...so I'm thinking it was partly the sand...it was from a sump and pretty dirty.

I need to move my Solana contents which does have SPS and a nice RBTA into the tank with the G2. They are currently under and LED fixture my hubby built that has a mixture of cree bulbs, 12 blue and 12 white bulbs at 3.7W's each. I'm thinking G2 will still do well for the corals as I have another RBTA in this tank recovering and it's coloring back up quickly. What are your thoughts? FYI...I got this light after I saw yours LOL...got in on a group buy for $400 including shipping.

Also do you use the mounting rack or did you suspend it and if so how high do you have it from the water? I don't know why, but I'm worried not suspending will put it too close to the corals and stress them out. I had a chalice on the side before, somewhat shaded and it started to bleach.

As far as my opinion on LED's...I really like the color. There is heat, but it's directed up. I actually have a heater on my Solana...usually stays about 78, but never goes above what the temp in the house is (80 when we are at work).

My schedule is similar:

blues on at 11:00

whites on at 11:30

whites off at 7:30

blues off at 8:00

I wish I had the moon lights from the G2... oh well. Next tax return.

Because of the weird shape of the tank, I've got my fixture resting on the rails on each long side. The LEDs are about a half inch from the plastic cover on the tank and that's about 1.2 to 1 inch from the water. So they are pretty close.

We have found that lower light species don't like the intensity of the LEDs, I'm guessing that would be true for MH as well. So we built kind of a shelf out of dead rock. It's about 2/3rds of the way tp the tank and provides shade for a big chunk of the bottom area. That's where all the zoas and mushrooms are. Most of the SPSs are on top of the shelf, right under the lights. The birdsnest and the softies do not like the intense light. We have some mushrooms that literaly crawled into the rocks to hide from one of the 30W spots.

I had a huge problem with hair algae recently. I reduced my photoperiod and installed a skimmer. The hair algae disappeared in about two weeks. We also got a tail spot blenny and he keeps algae in check too. I have other kinds of algae, but its not as annoying as the hair or cyano. Some of it's pretty, so I leave it and just trim it once every couple of weeks... which I need to do today.

I hope that helps.

Ogre

[Dena]

Thanks...I think my blues come on earlier...we've lost power a few times since it's been in and I bet it's a little screwed up. I"m going to adjust it all tomorrow. My husband put the hanging kit on this morning while I was in bed and it definitely lights up the tank more...and the moonlights disperse better also. Thanks for the info...wish I could afford four more for the large tank...but I'd have to buy the more expensive ones because it's a little taller than my 30 gallon. I've kind of a cube with the 30 gallon so it's not real tall...really hoping to put SPS in it.