brad65ford
New member
Great thread and a real reality to it. Are we being played by marketing? I've seen enough systems and also my own to know LED's are not a sure thing as much as MH.
Kessil A350W vs Metal Halide
- Thread starter Barbelist
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Reef Junkie
Premium Member
I know this is an old thread, which makes it even better to reply to.
After years of reefing with Halides, T5's, LED's, it's safe to tell the secret that the experts have always known... Metal halides will grow your SPS Reef faster than any other lighting system on the market.
The question is, do you really need to grow your corals that fast?
If not, maybe LED's are your best option?
LED's, while not nearly as powerful as some bulbs, like 400 watt halides, will still grow out your corals and give you great color and growth.
It's literally a matter of opinion at this point.
Quick grown and poppin colors, Metal Halides.
Slower growth with similar colors, LED's.
After years of reefing with Halides, T5's, LED's, it's safe to tell the secret that the experts have always known... Metal halides will grow your SPS Reef faster than any other lighting system on the market.
The question is, do you really need to grow your corals that fast?
If not, maybe LED's are your best option?
LED's, while not nearly as powerful as some bulbs, like 400 watt halides, will still grow out your corals and give you great color and growth.
It's literally a matter of opinion at this point.
Quick grown and poppin colors, Metal Halides.
Slower growth with similar colors, LED's.
biecacka
Active member
Bill, I don't think there is much of a question whether they grow coral or not. I hunk the big topic of discussion is number of units needed. I have a 48/48/24in tank that I light with a single 400watt bulb. According to the OP statement, I can replace that with a single kessil.....now I will admit all myrock and coral are in a 36/36 section of the tank, but I doubt that a single kessil or just about any led will cover that spread and produce enough par.
Corey
Corey
Reef Junkie
Premium Member
You and I both know a single kessil is not going to our perform a 250 watt 65k bulb. Even a 20k Radium has incredible power. My guess is you would need multiple LED fixtures to match the intensity of one metal halide.
Again, every expert I know use MH to grow out their corals. The acropora colony's grow perfect symmetrical patterns.
Where LED's tend to grow acropora colony's with more straight up.
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Again, every expert I know use MH to grow out their corals. The acropora colony's grow perfect symmetrical patterns.
Where LED's tend to grow acropora colony's with more straight up.
Sent from my iPhone using Tapatalk
Agree on all counts. Problem with LED (at least the premium fixtures like Radion and Kessil) is that they are point source lights and shading becomes a problem, particularly as colonies grow. BTW, MH is a point source too, but the use of large reflectors largely mitigates this. I've experimented with a lot of different combinations, and my judgment would be that something like the Kessil 360 is a HQI 150 replacement. I think you'd need two to replace HQI 250. Also, if you can stomach the cost, proper LED coverage is just as good at growing SPS an MH. Some colonies look better under LED, others under MH. Horses for courses.
Whether the majority of long-term SPS keepers use MH primarily is of course unprovable; though I'd assume it to probably be true, not so much because LED is necessarily deficient but because MH has a much longer track record of success and why move away from what works. Plus of course the $$$.
After having some in depth discussions with Dana Riddle and seeing that IR (maybe up to 850nm) is very helpful at moving energy from PSII to PSI, the supposition that there is no savings and you need a watt for a watt seems to be pretty true. Studies are coming soon, but if you are replacing 250W of high quality output, you will need 250W to replace it with. This has been suspected for a long time by some high end folks who have used both, but only anecdotally. A 90W kessil is not going to replace a 250W halide, but why would a manufacturer tell you otherwise when if you buy the first one, you will buy the second one from the as well.
Some of the high end euro LED units are coming with IR now. Expect the US and China ones to follow suit. If nothing else, they can sell more panels this way like they did when UV came out. Of course, this means more wattage. I would at least wait until the PhotoSystem study comes out from Riddle to see if you should wait and buy a panel with UV.
After this iteration and all of the cut spectrum is put back in, somebody is going to shine a cluster up into a reflector to mix color and spread better.
Most of the people who are into acropora like I am (and I know very well) are all MH primary systems. The main reason other than pure performance is that reflectors cover large tanks easier than panels... for a 8 foot tank, buying 4 new MH bulbs is cheaper than buying 16 to 20 T5 bulbs. They want stuff that works. I can promise you with 100% certainty that cost and dogma is not an issue - if I thought that 30 Radions would work better, I would spend the money in a heartbeat.
Some of the high end euro LED units are coming with IR now. Expect the US and China ones to follow suit. If nothing else, they can sell more panels this way like they did when UV came out. Of course, this means more wattage. I would at least wait until the PhotoSystem study comes out from Riddle to see if you should wait and buy a panel with UV.
After this iteration and all of the cut spectrum is put back in, somebody is going to shine a cluster up into a reflector to mix color and spread better.
Most of the people who are into acropora like I am (and I know very well) are all MH primary systems. The main reason other than pure performance is that reflectors cover large tanks easier than panels... for a 8 foot tank, buying 4 new MH bulbs is cheaper than buying 16 to 20 T5 bulbs. They want stuff that works. I can promise you with 100% certainty that cost and dogma is not an issue - if I thought that 30 Radions would work better, I would spend the money in a heartbeat.
greengeco82
Reefer
They dont compare. Halide wins! Now you can move on with your life.
Your question from 2014 is answered!
Reef Junkie
Premium Member
Omg, I literally lol'd when I read this! Hahaha
Thanks for the laugh.
All kidding aside, I think it just proves that the hobby is always creating new ways and technologies to try and just make more money off us.
Case and point, there was a time when Bio-Balls were the latest tech and you had to have them. (Sorry for reaching so far back)
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Wasn't aware that remained to be proven :lol:. Some years ago the famed SCIFI author Theodore Sturgeon noted that '90% of SCIFI is crud'. When pressed he further noted (or perhaps was paraphrased) that 90% of everything is crud. Reefkeeping is no exception. A great majority of the 'innovations' prove to be underwhelming, even useless, but in the 'noise' come a small percentage of really important new ideas. One must accept the 'chaff' in order to enjoy the 'wheat'.
I simply do not accept that LED cannot successfully grow out a SPS-dominated tank. I have taken the time to 'prove' it to myself (even if statistical significance is wanting) and am quite comfortable with my conclusions. As I noted before, I am sure that a great many long-tenured SPS keepers use metal halide - humans are creatures of habit of course, and MH has proven it's long-term viability. I'd also suggest that folks moving from MH to LED will find the promised savings elusive if they implement the latter properly (i.e. don't accept manufacturer recommendations as gospel).
This is a choice thing. If 400W of V4 is fine, then a pair of 150W HQI and T5s at about 400W would have been fine too and you did not need 900W of Spectra. If you DO need 900W of spectra, then you will need 900w of V4 to replace it with.
I do agree that people oft had too much lights, but bad choices are just bad choices and not a good part of a equivalency equation.
One thing that panels did make some people realize is that some did have too much light. If a single Kessil has enough light, then give a 70W Halide a try... you might never switch back.
Partly. PAR is mostly a joke - useful as PART of a plan, but not the WHOLE plan. It does not capture all of the output of some lights and often misses much of the important part of the spectrum.
PAR meters drop off under about 450nm and don't catch anything under 400. There is all kinds of output lower than 450nm for all tubes and Mh bulbs that shine well down to 350nm where nearly all true have proteins that excite. Some of the newer models are better, but still not great.
If you use a high end piece of equipment like an integrating sphere with a spectrometer, you can see that a watt of input is about a watt of output regardless of source - there are some inefficiencies with some lights, but lets take those out. MH (and to a lesser degree T5) have some IR that people think is a waste - it is being seen now that lack of UV can keep coral from moving energy between PSII and PSI and that all of it is not a waste. Dana Riddle is in the middle of studying this, but if it is found to be true (or even trueish), then there is no more argument that MH are not as efficient since the IR is indeed needed. If this seems crazy, remember back to the olden days of 2015 when people thought that UV was unnecessary (I am kidding, but only partially).
PAR is no way to measure the effectiveness of a light any more than horsepower can tell you how fast a car is.
Also, in your example, you are comparing 500 to 420 watts, not 900 to 400. When you look at a curve for a Apogee 210 PAR meter, for example, you can clearly see where the blue output is cut back which can easily make up for a 20% difference just in the measurement tools.
I know that people love them some BRS, but what did they use in that test? I can assure you that a good bulb like a 20K Radium or 14K Phoenix is a lot more than 250 PAR at 18 inches - more like 350 to 400 in the 12" center and probably 250 on the very edge of a 24" circle (depending on reflector). I can measure this when the lights come on - I have an Apogee 510 at the house. One video that I watched used a electronic ballast and some less-than-ideal bulb like a Giesemann 20K (I don't really remember) that is significantly less output than a best-of-breed light combo.
I would bet that if you got that spectra and put a good bulb in it like a 20K Radium on a good ballast and used a professional spectrometer and meter that it would put out 1.5 times as much output at the V4, but is also closer to 300w which is 1.5x the wattage. ...a wash.
This is a long way of saying that yes, a watt is basically a watt from the light. This leaves out the other factors like bulb changes, some heat (especially from 400 and 1000 watt MH), performance, just plain-old personal preference and some others which.
PAR meters drop off under about 450nm and don't catch anything under 400. There is all kinds of output lower than 450nm for all tubes and Mh bulbs that shine well down to 350nm where nearly all true have proteins that excite. Some of the newer models are better, but still not great.
If you use a high end piece of equipment like an integrating sphere with a spectrometer, you can see that a watt of input is about a watt of output regardless of source - there are some inefficiencies with some lights, but lets take those out. MH (and to a lesser degree T5) have some IR that people think is a waste - it is being seen now that lack of UV can keep coral from moving energy between PSII and PSI and that all of it is not a waste. Dana Riddle is in the middle of studying this, but if it is found to be true (or even trueish), then there is no more argument that MH are not as efficient since the IR is indeed needed. If this seems crazy, remember back to the olden days of 2015 when people thought that UV was unnecessary (I am kidding, but only partially).
PAR is no way to measure the effectiveness of a light any more than horsepower can tell you how fast a car is.
Also, in your example, you are comparing 500 to 420 watts, not 900 to 400. When you look at a curve for a Apogee 210 PAR meter, for example, you can clearly see where the blue output is cut back which can easily make up for a 20% difference just in the measurement tools.
I know that people love them some BRS, but what did they use in that test? I can assure you that a good bulb like a 20K Radium or 14K Phoenix is a lot more than 250 PAR at 18 inches - more like 350 to 400 in the 12" center and probably 250 on the very edge of a 24" circle (depending on reflector). I can measure this when the lights come on - I have an Apogee 510 at the house. One video that I watched used a electronic ballast and some less-than-ideal bulb like a Giesemann 20K (I don't really remember) that is significantly less output than a best-of-breed light combo.
I would bet that if you got that spectra and put a good bulb in it like a 20K Radium on a good ballast and used a professional spectrometer and meter that it would put out 1.5 times as much output at the V4, but is also closer to 300w which is 1.5x the wattage. ...a wash.
This is a long way of saying that yes, a watt is basically a watt from the light. This leaves out the other factors like bulb changes, some heat (especially from 400 and 1000 watt MH), performance, just plain-old personal preference and some others which.
Reef Junkie
Premium Member
I don't mean to call malarkey, but we all know that the "œsavings" is literally spent on other reef related things.
We're not fooling anyone.
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We're not fooling anyone.
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I just tested it out...
8" over the water is AquaMedic OceanLight with 250W 14K Phoenix on M80 Ballast. 18 inches deep and directly under the light is 378 PAR. Right next to the glass was lower than I guessed at 162 PAR - 2 inches in it was 242.
This is with Apogee 510 meter.
8" over the water is AquaMedic OceanLight with 250W 14K Phoenix on M80 Ballast. 18 inches deep and directly under the light is 378 PAR. Right next to the glass was lower than I guessed at 162 PAR - 2 inches in it was 242.
This is with Apogee 510 meter.
biecacka
Active member
My big thing is like simon said, most issues come not with the argument that leds can't grow coral, they can. But the number of units needed to equal halide. In my tank, 48/48/24 I would typically need 6-8 led units to prevent shadowing when 1-2 halides could do the right thing.
Now, I am aware of some lights like the orphek, ap700, and reefbreeders that cover a larger area because they are a larger light.
Corey
Now, I am aware of some lights like the orphek, ap700, and reefbreeders that cover a larger area because they are a larger light.
Corey
Most of the panels cover OK, but they aren't really strong enough. A light like AcroOptics is plenty strong and is a nice wide panel, but clocks in at quite a high wattage. Some of the other panels coming out have like an Radion 15 Pro equivalent x6 or x8 over a 2x2 area - this might be getting somewhere, but this will suck up the juice too.
To me, a Photon V2 at usable levels (diodes not burning coral with bad spectrum) is not even equivalent to a 150W HQI in a 2x2 area. However, that is plenty of light for the vast majority of people. I have not been around the other ones to get a good sense about them. I might be able to check out a V4 Orphek soon - I am somewhat excited about it having the widest spectrum available, but still think that they are disingenuous saying that it will replace a 400W MH.
To me, a Photon V2 at usable levels (diodes not burning coral with bad spectrum) is not even equivalent to a 150W HQI in a 2x2 area. However, that is plenty of light for the vast majority of people. I have not been around the other ones to get a good sense about them. I might be able to check out a V4 Orphek soon - I am somewhat excited about it having the widest spectrum available, but still think that they are disingenuous saying that it will replace a 400W MH.
Does anybody else find it interesting that the Orphek V4 has the 850nm UV on the same channel as the blues? You have to use it, and use a lot of it (relatively). This seems like a huge bet for them to provide UV to help with energy transport with the bulk of the waves so that you can drive them higher than other panels. If it works, this could actually be the next big thing in LED tech as less and less spectrum gets cut (or more and more comes back)... if not, then just another panel with different colors that goes by the wayside.
oreo57
Well-known member
That point is quite arguable on both a watt efficiency basis and simple geometry..
MH at best push 110L/ W while current LEd's are pushing up to 150L/ W
Combine this w/ geometry efficiency, 120 degree spread vs 360 degree spread and even w/ the best reflectors.. LEd's win
Now I'll def. give you 90W will not equal 250W but if you want to compare say the best LEd's w/ the best MH you will probably find that you do not need the same Watts of light..
Older,more optimistic estimates would put the ratio at about 1:2.
Unfortunately you were sold even more optimistic ratios on the order of 1:3
Poor efficiency diodes (Bridgelux, black box) would probably bring you to 1:1
simply due to the fact that LED efficiencies are only in the 50L/W range..
Keep in mind this is "At the bulb" efficiencies not "system watts"..
MH 65-115 L/W
White LED 4.5-190 L/W
for fun:
Keep in mind that these "whites" are blue w/ phosphors removed.
AFAICT MH "hit the wall" and probably will not be progressing much farther than this, w the exception of below.
This is from 2001..
Which "might" get you to 150 L/W
you still have geometry to fight..
Point is ..even w/ current "quality" diodes LED do have an edge in output vs power it was just never as much as you were sold..
Same analysis pertains to tubes..
T8 tube with electronic ballast 80–100 L/W
t8's are a wee bit more efficient than t5's
Unless proven otherwise.. See it being really close to a 400W MH...
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