Anyone Thinking of Dumping LEDS and going back to Halides

[karimwassef]

Keep in mind that Sanjay also lives in the cold north. I know, I got started into reef keeping with him in the early 90s at Penn State.

He uses the heat from the MH to heat the surroundings, so the energy savings benefits are of no value. He would have to spend it in heaters and heater power - both for the water and the air.

It's another example of individual optimization. What's good for one isn't necessarily good for another.

I also think that the discussion on spectrum matters a lot. Growth is not just a function of PAR. I disagree with his assertion that a photon is a photon. The photons are the same, but the way coral tissue and symbionts respond isn't.

The difference in growth among different coral species (mentioned earlier) under the same comparative lights is a great example of this. While the physics may be the same, the biology and chemistry are not. This is where LEDs can really help. The ability to tune a spectrum is only available with better access to more diverse LED constructions. I think that would allow us to really understand what works for each coral and then what may be the best for most.

 

[karimwassef]

Here is something interesting to look at. The first photo is of Sanjay's 500G after the 2 years on Radion LED. The second is his tank when he won TOTM lit by 3 - 400W Ushio 14K Metal Halide.

what do you see?

 

[AZRippster]

what do you see?

Nope, not falling for that. I just stuck them here for folks to look at for themselves.

 

[Jeremy257]

Logically speaking, if one can give any given coral the specific light spectrums it utilizes best for growth and coloration at the appropriate levels it will flourish (given appropriate water chemistry and flow). There most likely lies the crux. If I have a reef full of various species, the LED lighting to give every member of the population would need to be, well know one really knows for sure I think. With MH you don't have the gaps in spectrum that any modern LED (production or DIY) holds.

 

[karimwassef]

Nope, not falling for that. I just stuck them here for folks to look at for themselves.

fair enough. You're "folks" too. I'm curious what your personal view is - I couldn't draw any conclusions myself.

Noone can fault you for what you perceive as beautiful...

"les goûts et les couleurs ne se discutent pas"
http://context.reverso.net/traduction/francais-anglais/les+goûts+et+les+couleurs+ne+se+discutent+pas

 

[karimwassef]

Logically speaking, if one can give any given coral the specific light spectrums it utilizes best for growth and coloration at the appropriate levels it will flourish (given appropriate water chemistry and flow). There most likely lies the crux. If I have a reef full of various species, the LED lighting to give every member of the population would need to be, well know one really knows for sure I think. With MH you don't have the gaps in spectrum that any modern LED (production or DIY) holds.

well.. we do know what works all the time: sunlight. It's what they evolved to grow under.

But, some may be able to grow better under artificial conditions due to their unique biochemical response to certain frequencies.

MH is great, but it's relatively static (X metals release Y frequencies). LED is tunable with individual semiconductor dies - so it can teach us a lot more and potentially help develop better MHs one day. Or provide a daily varying spectrum that stimulates corals better.

For example, the sunlight on a real reef is very "red" at dawn and dusk. It's a function of the angle of the sun. It's very "blue" and "white" at noon. I've always wondered if these subtle daily spectrum changes could benefit corals that have evolved under these conditions.

For the longest time, we didn't know that moonlight has an effect on spawning. I set up a "UV" moon phase and I've got every non-sessile invertebrate and fish spawning in my tank... It's a freak fest in there. No corals yet.

 

[Fredfish]

fair enough. You're "folks" too. I'm curious what your personal view is - I couldn't draw any conclusions myself.

Noone can fault you for what you perceive as beautiful...

"les goûts et les couleurs ne se discutent pas"
http://context.reverso.net/traduction/francais-anglais/les+goûts+et+les+couleurs+ne+se+discutent+pas

Personally I don't like the look of the Radion tank because it is more blue than the Ushio 14K tank, but that is something that can be adjusted for.

 

[karimwassef]

I agree that "for me", blue tanks don't look real. That's because I snorkel and I see what they're supposed to look like.

They do look "prettier" - but not natural.

 

[milsaltnewbie07]

Leds to t5 here. Hoping i won't regret it

 

[Fredfish]

I agree that "for me", blue tanks don't look real. That's because I snorkel and I see what they're supposed to look like.

They do look "prettier" - but not natural.

Sigh, I wish I lived closer to a tropical ocean. The best pictures I took on the Great Barrier Reef were at 3 - 5 meters: such vibrant colours!

 

[Jeremy257]

I'm most certainly a novice with SPS. I want to be able to utilize tried and true methods for successfully creating a beautiful reef in my home to enjoy. I think it is safe to say that I will grow frags quickest across most species using MH.

I got the SPS fever when I found an amazing LFS last year. They grow the kind of amazing SPS I only saw before online. Everything there is grown under MH. A new found friend who does aquarium maintenance for a living recently showed me his own personal 400g tank he set up only months ago. When I saw the great growth he had already gotten out of his frags I knew I had to take a different approach. He uses 400w Radiums. I want this kind of growth.

I am meticulous with water quality. I use 2 part dosing. I maintain low, but existent, nutrients in my water column. I feed the reef well. I've got strong, alternating flow. I've tried a few different types of LEDs. My SPS frags have solid color but the growth sucks when I now compare it to what I know is possible. I'm sure there are probably more factors at play than just light. But I want to remove that parameter.

 

[AZRippster]

fair enough. You're "folks" too. I'm curious what your personal view is - I couldn't draw any conclusions myself.

Noone can fault you for what you perceive as beautiful...

"les goûts et les couleurs ne se discutent pas"
http://context.reverso.net/traduction/francais-anglais/les+goûts+et+les+couleurs+ne+se+discutent+pas

I'm a guy that has gone from MH/VHO to LED and back to MH/T5, at least for the interim. I do believe LED can and will do a good job, but coverage is a big thing and with Sanjay having as many Radions as he has over his tank, he's getting the coverage (although he still complains about shadowing and "œdisco"). There are some mighty beautiful LED exclusively lit tanks, but most I have seen posted are in the sub-200G size. As you eluded to, taste is very subjective. Personally, I'm like you, I like the whiter look. I'm a diver and have never seen Windex coral on any dive I have made. At the same time, many dives do not reveal the true color potential corals may reveal. Get down around 100' and most lose all their color unless you shine a dive light on them. Next month I'll be diving the Keys, and due to its naturally shallower reef line (and sadly die off), much of the corals appear washed out. I have thought many times how much I would love to try some of them in a controlled environment. Back to Sanjay's tanks, his TOTM was from 2009 whereas the Radion lit version is a couple months fresh. I personally prefer the MH/T5 look, but the LED lit version has its pros as well.

 

[oreo57]

I disagree with his assertion that a photon is a photon. The photons are the same, but the way coral tissue and symbionts respond isn't.

The difference in growth among different coral species (mentioned earlier) under the same comparative lights is a great example of this. While the physics may be the same, the biology and chemistry are not.

disagree, photons are photons.. only quantities at certain levels changes..
It is practically impossible to have the exact same spectrum between MH's and LED's. Their creation is physically different .. but their "products" are identical..on a quantum level..
Like I said earlier Radions are not in any way "spectral equivalent" to any MH..
The lack of lower nm components (and some upper level components) makes them non-equvalent in a broad sense.. not just narrow bands..
If someone can prove to me a 660nm vibrating photon from an LED is "different" than a 660nm one from an LED I would like to see that...
Stranger things have happened though..

All photons of equal frequency have the same energy.

David Simmons-Duffin, Physicist
3k Views • Upvoted by Steve Byrnes, Postdoc in Physics, Harvard University, Shreyes Seshasai, B.S. Physics from MIT, Debo Olaosebikan, Physics PhD. candidate at Cornell
David has 8 endorsements in Physics.
https://www.quora.com/If-you-have-t...d-that-mean-would-the-photon-have-more-energy

 

[ca1ore]

I've been running my tanks for over three years on LED and here's what I've experienced:

1. The cost difference is not negligible, but it is modest. I don't think you do it just based on cost.
2. Growth has been just fine on all my corals, even SPS. Whether it would have been faster with MH (and whether that's a good thing) is debatable. In my case, my bali slimmer has grown like a weed.
3. Coloration is about the same.

IMO the 'issue' is that MH is predictable and reproducible, whereas LED is not. Too much mucking around with LED swapping, ramping, and all that other crap makes it hard for folks newer to the hobby to figure out where to start. The other issue is that problems with corals are so complex, and dependent upon so many things, that it is almost impossible for the novice reefer to work out causes versus just correlations.

To my friends entering the hobby I recommend either MH or T5; however, I will never go back myself.

 

[Jeremy257]

Can't help but re-post:

https://www.reefs.com/blog/2016/01/0...0-gallon-reef/

 

[Jeremy257]

Ca1ore - thanks and agreed that someone like myself (Novice with SPS) is better off going with a staple like MH or T5.

 

[karimwassef]

disagree, photons are photons.. only quantities at certain levels changes..
It is practically impossible to have the exact same spectrum between MH's and LED's. Their creation is physically different .. but their "products" are identical..on a quantum level..
Like I said earlier Radions are not in any way "spectral equivalent" to any MH..
The lack of lower nm components (and some upper level components) makes them non-equvalent in a broad sense.. not just narrow bands..
If someone can prove to me a 660nm vibrating photon from an LED is "different" than a 660nm one from an LED I would like to see that...
Stranger things have happened though..


David Simmons-Duffin, Physicist
3k Views "¢ Upvoted by Steve Byrnes, Postdoc in Physics, Harvard University, Shreyes Seshasai, B.S. Physics from MIT, Debo Olaosebikan, Physics PhD. candidate at Cornell
David has 8 endorsements in Physics.
https://www.quora.com/If-you-have-t...d-that-mean-would-the-photon-have-more-energy

I meant that the fact that a "photon is a photon" doesn't matter. It's the effect of the photons on biological tissue that matters. Frequency and spectrum and angle do matter. I have a science degree too

 

[oreo57]

I meant that the fact that a "photon is a photon" doesn't matter. It's the effect of the photons on biological tissue that matters. Frequency and spectrum and angle do matter. I have a science degree too

then you should agree w/ the fact that if I took hundreds of specifically phosphored LEDs whose photon output equaled a MH bulb and mounted them on a corn cob and stuck it in a MH reflector it would indeed be equal...

none of the above is "impossible" btw...

In other words it is NEVER LED's but their specturm and spacial placement..
sometimes your words don't quite sound that way. My mistake..

But:

It's the effect of the photons on biological tissue that matters.

Photons from LED or MH or the sun for that matter.. makes no difference.. Statement makes no sense as I'm understanding it..

 

[ca1ore]

Can't help but re-post:

https://www.reefs.com/blog/2016/01/0...0-gallon-reef/

Trouble with that 'study', and I'm sure SJ would agree, is that it's a sample size of one. As such, it has no statistical significance at all and is no more useful than anything you or I would observe on our own tanks. Whether LED is better, or T5 better or MH better is almost academic as all three can be made to work perfectly satisfyingly in most implementations.

As I noted earlier, the issue with LED is it's inherent flexibility, and it may be difficult for the new reefer to be successful because of that. Most people here are too young (or not enough years in the hobby) to recall when MH had analogous issues. I bought my first MH fixture in 1988, and there were no reef-specific bulbs to buy so you had to play around with different choices. And it created problems.

I don't think that there's much doubt that LED will replace MH - probably sooner than later - in most reef tank implementations. I certainly have no plans to go back - for me, LED is simply better.




These two pictures are approximately two years apart; grown almost exclusively under LED. The most dramatic growth has been of the bali slimmer, the monti and torch coral. A couple of colonies have died; though not until after installing a few frags in the frag tank . Causes of death varied - from crowding/shading/stinging, to a mysterious bacterial issue that ate some colonies, to some fish damage.

FWIW, unless you plan to be a frag-factory, I'm also not sure that high growth rates are necessarily a good thing. It's more about consistency. After that first picture (the more recent one) was taken I had to do some pretty serious pruning of a number of corals. Filled up the frag tank an still had to throw a bunch out. PitA.

 

[markalot]

then you should agree w/ the fact that if I took hundreds of specifically phosphored LEDs whose photon output equaled a MH bulb and mounted them on a corn cob and stuck it in a MH reflector it would indeed be equal...

none of the above is "impossible" btw...

In other words it is NEVER LED's but their specturm and spacial placement..
sometimes your words don't quite sound that way. My mistake..

That exact thing has been said here many times. Spectrum plus delivery equals identical. I have yet to see a corn cob LED array that can duplicate the spectrum of a Radium (or T5 combination) that used a big reflector to spread the light out into a tank.

The main two points of argument here are spectrum and spread IMO. LED can't do the sharp peaks, or it's not cost feasible yet, can't do the green peak (lime maybe comes close, or it's simply cost prohibitive). and I have seen some doubt that reflectors would work as well since the LED point source is rather narrow vs a charged element reflected from a reflector.

Light is light, directionality is directionality, hot spots are hot spots. We have strong evidence of what works, why don't LED mfgs try and duplicate it?