Replacing 400W MH Pendants w/ LED Floodlights?

[jda]

Anybody who wants to believe this should watch this all the way through... or at least from about 24 minutes. This backs up everything that people with actual experience have seen over their tanks.

 

[danoo]

jda convinced me a few years ago on a different forum to light my 8' x 3' tank with MHs. I'm glad he did. I don't think he is being rude. He is clearly right and there is a lot of incorrect information in this thread.

If you calculate the numbers purely on a watt vs efficiency basis, LEDs might win *slightly*. However, LED units are *significantly* more expensive than MHs for the same amount of wattage. So much so that the difference in cost cannot be made up over the expected lifetime of the LED units.

Also there is no point in arguing what MHs are like without reflectors. The fact that you can have big wide reflectors is a huge advantage of MHs because you can get really wide spread out of one fixture.

LEDs are controllable, they are sleek looking, easier to install, and they bring out a different type of color in corals. They are a very useful light source for reef tanks. However, in terms of lighting up a wide area for the lowest overall price, I don't think it is even close in terms of comparing MH to LED.

 

[hart24601]

My lfs has a large tank, around 1200g and it’s at least 48” if not more. They swapped from using mh to those maxspect units and last I spoke with them they were really happy and in that tank with acros and mixed corals they seemed to outperform the MH.

The manager Tim is nice and loves to talk reef. I suggest you give Iowa seascapes a call and ask to talk with Tim about it. I don’t have their number but you can call them. I think they replaced 2 1000w units with 4 maxspect but I can’t remember for sure.

 

[Bpb]

Obviously If the challenges of metal halide lamps are able to be managed for you I can’t think of a good reason to switch lighting methods. Theory is fine all day but if your tank is trucking along as is and you’re not unhappy I don’t think changing will make you happier

 

[oreo54]

jda convinced me a few years ago on a different forum to light my 8' x 3' tank with MHs. I'm glad he did. I don't think he is being rude. He is clearly right and there is a lot of incorrect information in this thread.,

You should list it and correct it for others.

in terms of lighting up a wide area for the lowest overall price, I don't think it is even close in terms of comparing MH to LED.

Overall cost wasn't what the o/p asked about. Pretty sure it's obvious that a $300 mh ballast/reflector/400 w bulb is more expensive than a 320w led at $800.

 

[oreo54]

Obviously If the challenges of metal halide lamps are able to be managed for you I can’t think of a good reason to switch lighting methods. Theory is fine all day but if your tank is trucking along as is and you’re not unhappy I don’t think changing will make you happier

However, I live in Florida and my primary motivation to possible consider moving away from MH would be to cut down on heat transfer to the water (and the room ;)), thus decreasing house A/C usage, aquarium chiller usage, evaporation, and humidity. Even if it would only be possible to cut down on these a small amount, I feel that it could add up over time due to the volume of water. Also, avoiding having to replace constantly replace bulbs to maintain maximum performance and PAR would be a nice benefit on decreasing the maintenance routine a bit
Thought these might be a more cost-effective solution versus buying 10-15 LED pucks at $600-800 a piece. Searched and didn't find much on this, I'm assuming since even the smallest ones would be way overkill for most tanks...

Orig op question ....

 

[Bpb]

Overall cost wasn't what the o/p asked about. Pretty sure it's obvious that a $300 mh ballast/reflector/400 w bulb is more expensive than a 320w led at $800.

the one area of contention I have here is if someone is SWITCHING, that argument doesn’t hold. If someone is setting up a brand new tank, it is absolutely something to consider, seeing as startup costs will be a lot closer than they are given credit for if purchasing all new hobby grade gear. But if someone already owns working MH gear (like the OP) and is considering a switch, I would expect Savings to generally be out of the discussion entirely, and for other tangible factors to be at play. Such as heat/humidity management, overall aesthetics, ect

 

[Bpb]

Orig op question ....

right. That was the spirit of my
Above comment I made as you were posting this one.

at the end of the day it is a gamble he has to Make. Nobody can say if performance will be comparable because that will depend on the execution of his application. To what degree are the other challenges of MH inconvenient? Are we just flirting with the idea of the grass being greener on the other side? Or is our mind made up, it’s too much to handle, and now we are genuinely picking between led options. I don’t like to try to sway someone toward one tech vs another. I try to at least be as helpful in answering specific questions without adding in unnecessary recommendations.

 

[oreo54]

the one area of contention I have here is if someone is SWITCHING, that argument doesn’t hold. If someone is setting up a brand new tank, it is absolutely something to consider, seeing as startup costs will be a lot closer than they are given credit for if purchasing all new hobby grade gear. But if someone already owns working MH gear (like the OP) and is considering a switch, I would expect Savings to generally be out of the discussion entirely, and for other tangible factors to be at play. Such as heat/humidity management, overall aesthetics, ect

That is for them to decide.
Obviously the op thinks they have an "issue".
There is no doubt mh's transfer more heat down and into the water than led's.
Do we agree?

320w vs 400w is less heat
Agree?

 

[Bpb]

That is for them to decide.
Obviously the op thinks they have an "issue".
There is no doubt mh's transfer more heat down and into the water than led's.
Do we agree?

320w vs 400w is less heat
Agree?

absolutely. Even if run at the full 320 watts the heat won’t be put directly down to the water. Don’t mistake me for thinking it’s a bad idea to switch. I’ve recently dealt with the exact same issue myself

 

[ElussssvReefSD]

My lfs has a large tank, around 1200g and it’s at least 48” if not more. They swapped from using mh to those maxspect units and last I spoke with them they were really happy and in that tank with acros and mixed corals they seemed to outperform the MH.

The manager Tim is nice and loves to talk reef. I suggest you give Iowa seascapes a call and ask to talk with Tim about it. I don’t have their number but you can call them. I think they replaced 2 1000w units with 4 maxspect but I can’t remember for sure.

Why thanks I think I will do just that! Appreciate the tip!

 

[ElussssvReefSD]

the one area of contention I have here is if someone is SWITCHING, that argument doesn’t hold. If someone is setting up a brand new tank, it is absolutely something to consider, seeing as startup costs will be a lot closer than they are given credit for if purchasing all new hobby grade gear. But if someone already owns working MH gear (like the OP) and is considering a switch, I would expect Savings to generally be out of the discussion entirely, and for other tangible factors to be at play. Such as heat/humidity management, overall aesthetics, ect

To be clear, because perhaps I wasn't in my original post, I already have the MH gear that is more or less brand new from a previous build. This is for a new build but with already "broken in" gear.

However, the only rationale behind even considering a switch to LED would be for heat transfer mitigation and the en-suing decreased costs of chiller use/room ac/evaporation. AND ONLY if there was an LED option that could be swapped out one MH fixture for a single LED fixture. That's all.

Thanks for the discussion, all of you have given me much to think about, and I promise never again to touch any of the other third rails of reef-dom... : "sand or no sand", and "acrylic or glass" LoL ;Hilarious

 

[danoo]

To be clear, because perhaps I wasn't in my original post, I already have the MH gear that is more or less brand new from a previous build. This is for a new build but with already "broken in" gear.

However, the only rationale behind even considering a switch to LED would be for heat transfer mitigation and the en-suing decreased costs of chiller use/room ac/evaporation. AND ONLY if there was an LED option that could be swapped out one MH fixture for a single LED fixture. That's all.

Thanks for the discussion, all of you have given me much to think about, and I promise never again to touch any of the other third rails of reef-dom... : "sand or no sand", and "acrylic or glass" LoL ;Hilarious

As a thought experiment, which I'm actually quite interested in as I'm about to move to a warmer climate...

Assume we had a 400watt LED fixture and a 400w MH fixture over our tank, which we all agree are going to produce 400watts of heat. The 400w MH fixture is going to radiate most of the heat downwards into the tank and some amount in the surrounding air. The LED fixture is going to concentrate the heat around the heatsink, which will radiate into the surrounding air around the heatsink.

With the MH bulbs, a lot of the heat is going to be absorbed by the water, and then very slowly radiated out into the surrounding air (assuming a house with a relatively normal ambient temperature). With LEDs, the heat is just radiating directly into the air.

Is the supposed advantage of LEDs is that the heat radiating into the air is easier to deal with, or that we expect to get by with less overall wattage and therefore less heat, or both? The maxspect website is making the argument that you can get by with less wattage, but obviously there are conflicting views about that (third rail of reefing!).

I can imagine situations where with some intelligent ventilation you could export the heat from the LEDs to the outside pretty efficiently, is that the idea? Otherwise in a closed environment (like a house), no matter whether it is LEDs or MHs producing the wattage, the A/C is going to eventually have to deal with the heat just the same.

 

[Bpb]

As a thought experiment, which I'm actually quite interested in as I'm about to move to a warmer climate...

Assume we had a 400watt LED fixture and a 400w MH fixture over our tank, which we all agree are going to produce 400watts of heat. The 400w MH fixture is going to radiate most of the heat downwards into the tank and some amount in the surrounding air. The LED fixture is going to concentrate the heat around the heatsink, which will radiate into the surrounding air around the heatsink.

With the MH bulbs, a lot of the heat is going to be absorbed by the water, and then very slowly radiated out into the surrounding air (assuming a house with a relatively normal ambient temperature). With LEDs, the heat is just radiating directly into the air.

Is the supposed advantage of LEDs is that the heat radiating into the air is easier to deal with, or that we expect to get by with less overall wattage and therefore less heat, or both? The maxspect website is making the argument that you can get by with less wattage, but obviously there are conflicting views about that (third rail of reefing!).

I can imagine situations where with some intelligent ventilation you could export the heat from the LEDs to the outside pretty efficiently, is that the idea? Otherwise in a closed environment (like a house), no matter whether it is LEDs or MHs producing the wattage, the A/C is going to eventually have to deal with the heat just the same.

Something else to consider is you generally don’t apply the same amount of par with leds that you do with halides. I would not hesitate to throw 400+ par at an lps coral with 14,000k metal halides but you
Better believe I wouldn’t do that with an led fixture. Same goes for sps corals. I’d not hesitate to hit an acropora or montipora with upwards of 1000 par with a metal halide, but I wouldn’t really flirt with much more than 400 par on an led fixture.

I’m not arguing spectral quality or growth effectiveness. I’m just saying that watt per watt isn’t exactly an apples to apples comparison. I went from 500 watts of metal halide providing about 600 par on average at the top of the rocks to roughly
About 200 watts of led lighting providing around 400 par at the top of the rocks which is about as high as I’d go.

The metal halide pendants were nearly too hot to touch when running and my arm would start to bake uncomfortably when working in the tank directly under them. I was evaporating 2.5+ gallons per day in my little 1200 sqft house. Running 80%+ humidity inside, AC running literally constantly, getting rust all over metal fixtures and vents inside the home and tons of mildew.

The led fixture runs literally cool to the touch at 200 watts and I evap about 0.5 gallons per day now.

I’ll reiterate. I LIKE metal halide lighting. I love the look and I love it functionally. It is a zero effort lighting source that is virtually infallible from a growth and color standpoint. I’m just getting at switching may not always be a direct watt per watt equivalent depending on your application. And that I completely sympathize with the OP. When you’re in a hot climate, the heat and humidity can become a very real problem

 

[danoo]

Something else to consider is you generally don’t apply the same amount of par with leds that you do with halides. I would not hesitate to throw 400+ par at an lps coral with 14,000k metal halides but you
Better believe I wouldn’t do that with an led fixture. Same goes for sps corals. I’d not hesitate to hit an acropora or montipora with upwards of 1000 par with a metal halide, but I wouldn’t really flirt with much more than 400 par on an led fixture.

I’m not arguing spectral quality or growth effectiveness. I’m just saying that watt per watt isn’t exactly an apples to apples comparison. I went from 500 watts of metal halide providing about 600 par on average at the top of the rocks to roughly
About 200 watts of led lighting providing around 400 par at the top of the rocks which is about as high as I’d go.

The metal halide pendants were nearly too hot to touch when running and my arm would start to bake uncomfortably when working in the tank directly under them. I was evaporating 2.5+ gallons per day in my little 1200 sqft house. Running 80%+ humidity inside, AC running literally constantly, getting rust all over metal fixtures and vents inside the home and tons of mildew.

The led fixture runs literally cool to the touch at 200 watts and I evap about 0.5 gallons per day now.

I’ll reiterate. I LIKE metal halide lighting. I love the look and I love it functionally. It is a zero effort lighting source that is virtually infallible from a growth and color standpoint. I’m just getting at switching may not always be a direct watt per watt equivalent depending on your application. And that I completely sympathize with the OP. When you’re in a hot climate, the heat and humidity can become a very real problem

This is very much a lower wattage argument. You switched from 500 watts of high quality lighting to 200 watts of high quality lighting. You had excess light before, you lowered the lighting to a level that was still fine for your goals and everything was great. But it isn't necessarily a convincing data point for this thread.

If you tank had *needed* 500 watts of high quality lighting, then your A/C would be working just as hard whether that wattage was coming from LEDs or MHs. Now obviously at your levels of light requirements, even the smallest MHs are probably too big so this is a clear case where LEDs make sense.

However, the OP is talking about replacing 400watt MHs with LEDs which are consuming around the same wattage. I highly doubt the OP could get away with reducing the lighting wattage by >50% and still achieving the lighting needs of the tank.

However... if the OP wanted to go the direction of lower wattage... why not simply start first with replacing a few of the 400watt fixtures with 250watt fixtures and then see what happens? That will lower the overall heat, the water temperature and the evaporation by significant amounts.

Again, LEDs have other advantages and I don't want to pretend LEDs and MH are the same. There are tradeoffs. But I think a lot of people get into LEDs thinking they will get the same amount of light for far less wattage and many real-world cases would show that isn't the case. Your PAR measurements showed that in your specific case how large a drop in light intensity there was from the LEDs.

 

[oreo54]

This is very much a lower wattage argument. You switched from 500 watts of high quality lighting to 200 watts of high quality lighting. You had excess light before, you lowered the lighting to a level that was still fine for your goals and everything was great. But it isn't necessarily a convincing data point for this thread.

If one "does the math" what does it say?

I went from 500 watts of metal halide providing about 600 par on average at the top of the rocks to roughly
About 200 watts of led lighting providing around 400 par at the top of the rocks which is about as high as I’d go.

Granted nothing different is exactly the same but......:)
If it holds all they'd need is 300W of LEDs to get 600 PAR

 

[fredk]

...

Current LED's are producing 100-140 Lumens/watt. Each color differs though and like w/ the LUX problem non-white colors on the edges of the Lumen chart usually are not measured in Lumens but in mW..

...

There are now some LEDs pushing 190 lumens/watt. Check out the Samsung LM301b/h. There are a bunch of companies using boatloads of these cheap-as-chips chips running in their peak efficiency band to produce low cost grow lights.

Not so useful for salt water aquariums, but still, LEDs for broader application markets are reaching the efficiencies and economies of scale we hoped for in the aquarium hobby a few years back.

 

[oreo54]

There are now some LEDs pushing 190 lumens/watt. Check out the Samsung LM301b/h. There are a bunch of companies using boatloads of these cheap-as-chips chips running in their peak efficiency band to produce low cost grow lights.

Not so useful for salt water aquariums, but still, LEDs for broader application markets are reaching the efficiencies and economies of scale we hoped for in the aquarium hobby a few years back.

Actually it sort of is useful since "white" LED's are generally royal blue or blue emitters plus phosphors..
Increased "lumens" means increase royal blue/blue photons..
Phosphors do not increase photons..AFAICT. ;)

NOW if one could get an LED manuf to "dope" these high emission diodes w/ a "reef pack" of phosphors one would no longer need this RGB ind. diode stuff like they eventually did w/ t5's MH's and to a certain degee in hort. to HPS ("whiter " HPS were created I "believe")

Technically what Kyocera did except using a violet pump..Sadly, violet emitters are not near as efficient as royal blues and blue phosphors (last I looked) aren't near as stable as the rest..

 

[blasterman]

Metal halides increase in efficiency as the wattage increases, and rival most LED at 1000watts when it comes to certain spectral lines. HPS for example is still competitive in high wattage bulbs.

LED tech is optimized for lumen output, not emitting 450nm light only. Lumens are weighted towards green for visual sensitivity and doesnt have much relevance for reef applications. If you were trying to light a football stadium for TV even 1000watt halides would get thumped by current LED tech in terms of energy savings. The 1000watt halide would do better if you only cared about 590nm and were lighting a parking lot.

What kills halide is fixture efficiency. LEDs are far easier to direct light than a big fat hot fire bottle and this alone amounts to 25% or more efficiency for LED. Only advantage T5 has over T8 is improved strike back efficiency due to smaller bulb size. That's it.

Reef LED fixtures are also not designed for high density, high power and efficiency like dedicated LED office light fixtures are. Reef LED fixtures use a handful of 3watt LEDs that hit a wall and dont scale, and this is by design. They want you to buy multiple fixtures at absurd cost. A reef LED light with 10 different color LEDs is going to be limited in terms of raw PAR efficacy because it's more related to a DJ or party light than a premium LED fixture over a warehouse designed to provide maximum lighting efficiency.

I could easily design and build a dedicated LED fixture that would crush a 400 or 1000watt Halide with a 40% or more energy savings at the same PAR for coverage. Be easy using Luxeon Ks which I have being shipped now. The reef lighting industry though doesnt want to build a light like this because they would be cutting their own throat. Black boxes are a different matter, and while they scale more linear they are limited with their low inherent efficiency.

 

[A. grandis]

Halides are very efficient when used with the proper fixture and wattage, providing a more complete spectrum to the system. Huge difference in the long run! T5s will embrace as a blanket and both will work together as the best artificial light available for any reef tank.
Energy efficiency in terms of "energy savings" is something very common to hear as a comparison with LEDs. Even LED companies use that all the time to sell. That doesn't happen always (heat/cooling needs) and many of us know that practically! Actual results are what most of us really want! There is a huge advantage when using halides and T5s over any reef tank. Those who actually try know what I'm talking about. Too many numbers and too much talk... graphics... etc... the results are different and most of us will prefer halides, if you forget the "excuses" around it. My preference goes to halide/T5s, besides natural light over the natural reef. With all the respect... if energy savings is what one is looking for, then get a smaller system with better quality and have your corals show their glory! They will love you forever! Remember: the initial cost of LEDs will kill you too! Go simple! Go complete! Go halide/T5 and call it a "great sunny day"!
Please go watch the video from post #21!