ComforablyNumb
New member
Can anyone tell me how much mH bulbs lose PAR and color-shift over a one year period?
Anyone Thinking of Dumping LEDS and going back to Halides
- Thread starter Goldcoastreefs
- Start date
drummerboyevil
New member
ComforablyNumb
New member
Thanks drummerboy! Seems like the average intensity loss is 15%-25% with the majority of the drop-off occurring in the first few months. So mH's are really operating at less than advertised intensity for the majority of their useful time? Or am I misreading that?
I would also like to see how the color shifts over time with mH if anyone knows that..or has a source that indicates it. Thanks again.
I would also like to see how the color shifts over time with mH if anyone knows that..or has a source that indicates it. Thanks again.
karimwassef
Active member
It's true that MH lose PAR, but they start at a higher PAR (even though that PAR comes at a poorer efficiency relative to power consumption).
So a 400W MH runs at 10% efficiency = 40W of light on day one, deteriorating to 80% of that = 32W of light.
And a 100W LED runs at 20% efficiency = 20W of light... with little degradation (assumed) = 20W of light.
https://en.wikipedia.org/wiki/Luminous_efficacy
As long as you take all those factors into consideration, you can figure out how much light you're really getting.
Get a PAR meter - you'll be happier
So a 400W MH runs at 10% efficiency = 40W of light on day one, deteriorating to 80% of that = 32W of light.
And a 100W LED runs at 20% efficiency = 20W of light... with little degradation (assumed) = 20W of light.
https://en.wikipedia.org/wiki/Luminous_efficacy
As long as you take all those factors into consideration, you can figure out how much light you're really getting.
Get a PAR meter - you'll be happier
And yet, I've seen others who have had success with acropora using Radions. Confuzzled stuff...
Indeed. Personally I've never liked the look of an all T5 tank. I'm also not a fan of high K MH. I just don't like the blue shifted look.
As to the missing green in LEDs I'm a little surprised that the Luxeon lime has not found wider use in LEDs. For those fixtures using them, the colour balance, with the appropriate settings, is quite good.
Concerning efficiency and radiated watts, here are some tests from an integrated sphere - nobody should be factoring in general lighting efficiencies with reef stuff since warehouses, streetlights, etc. don't contain and reflect light like a reefer does. Note that the kessil and radion are at 100%, which nobody would do. The Ushio was on a Icecap 250 electronic, which not too many people would do nowadays - that bulb does not have very good output and neither does the ballast. At normal output numbers (not 100%), you can see why Sanjay (and others) need 2 Radions to replace a 250W Halide and 3 to replace a 400W Halide. I cannot believe how bad the Kessil is for efficiency.
Ushio 250W (14K): 41W Radiated/ 250W input = 16% Efficiency
Kessil A350W (both channels high): 13W Radiated/ 90W input = 14% Eff.
Echotech Radion XR15W (all channels 100%): 17W Radiated/ 73W = 23% Eff
I love this guy since this guy did something and not just googled stuff. I would donate money for him to do more - like Radium 20K on M80 or XM/Hammy 10K on M58.
Post
http://www.reefcentral.com/forums/showthread.php?t=2404334
Ushio 250W (14K): 41W Radiated/ 250W input = 16% Efficiency
Kessil A350W (both channels high): 13W Radiated/ 90W input = 14% Eff.
Echotech Radion XR15W (all channels 100%): 17W Radiated/ 73W = 23% Eff
I love this guy since this guy did something and not just googled stuff. I would donate money for him to do more - like Radium 20K on M80 or XM/Hammy 10K on M58.
Post
http://www.reefcentral.com/forums/showthread.php?t=2404334
slief
RC Sponsor
In reading that thread, I didn't get that at all when it comes to the Kessils. Since blue light (Kessils strong point) doesn't read well by a par meter, there is no deriving the efficiency from that kind of a reading. Also keep in mind that corals get most of their needed photosynthetic radiation from the blue spectrum (Kessils strong point).
In fact, the OP of that thread says and I quote him: "Basically, I think what this says is that you get about the same amount of light per watt with either system, but the kessil might have an advantage with coral growth, as it dumps more of its energy into the blue. " He is comparing metal halide to Kessil 350.. Not even the 360WE. Also, he is running the channels at 100%. The Radion has Red, Green and more white LED than the Kessil does which will provide more output in readable spectrum but you would never run the Radions in that manner. Nor would you run the Kessil at 100% color which is more of a white shift. As such, while is results are interesting, a better comparison would be to test the lights in the manner they would be used instead of running them with all channels at 100%. The reality is that both the Radions and the Kessils are very well suited for any kind of corals growth. My SPS growth under Kessils has been phenomenal. I have a friend who uses Radions without supplemental lighting and his SPS growth is insane too. I think the biggest issues with LED's is how people are using them and or the source of the corals. Either will grow SPS great. Some frags may respond better than others but both are very well suited for growth. Radions are nice because they include controllable channels such as red and green which are great for using artificial light to bring out colors in corals that you wouldn't normally see in the ocean. The Kessil 360's lack those controllable diodes so you might not get the Reds and yellows to pop the way you would under a Radion Pro or even the Kessil AP700 now that Kessil has those channels under control with the latest beta app.
slief
RC Sponsor
What is really interesting to me is that 6 years ago, I was running two 400 watt Radium halides and six 4' VHO fluorescent bulbs (a total of about 1460 watts) and with my 8 Kessils running at 80% intensity (a total of 570 used watts during my 4 hour peak intensity period), I am seeing equal or better growth across the board on all coral types. Granted, my overall water quality is probably better now than it was then but still, judging by the growth shown above of SPS and LPS, watt for watt, LED's like the Kessils are pretty efficient when it comes to producing light needed most for coral growth.
ComforablyNumb
New member
oreo57
Well-known member
first the minor dig was for those who say the posted LEd spectral charts are garbage and all marketing. They seem to believe that posted spectra "lie" in their representation. Like there are large hidden "holes" in the data that are smoothed over because measuring equipment isn't that good..or people lie.
There is a small partial truth in that BUT not nearly to the extent some seem to want people to believe. A while back I posted data on some leds where the measurements were done in a few nM increments showing a relatively smooth progression around a central peak...Of course if ones position is you can't measure things that precisely well there is no winning an argument on those grounds. It becomes a matter of faith...
using that logic one wonders why graphs like this are not held to the same standard?
Aquablue Plus Spectrum (just picked one)
BTW using 20% as a baseline throws out a whole bunch of wavelengths in the above..
Granted the large spikes throw off the overall so technically a little unfair.
Or this:
As to included/not included/ wavelengths... that is a whole different ball game..
The second point is if there is some "magic wavelength" that is inherent in t5/MH it is not that LEDs are incapable (except for some very random fluke)
just that LED "as designed" are incapable..
Maybe some species need a mercury spike emission..Or maybe the teeny tiny amount of sub 380nm light in the above 20000k/10000k mh chart.
And yes I also don't consider the Kessel sub 400nm light output significant.. but again , you may be holding it to a different standard.
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oreo57
Well-known member
first off you are missing "overall"efficiency...
Not sure why he switched to 250 later..Oversight?
giving you 13.6 not 16%..
Secondly an integrated sphere in no way reflects the actual "geometry" of the light..Large bulbs radiating 360 degrees w/ wrap around reflectors of what quality vs. the same for an LED which radiates around 140 degrees and is then lensed to a smaller spread.. Point is even an integrating sphere can't compensate for actual design..
How much of the MH was so far off axis as to be unavailable to the tank? How much of the LED?
Point is EVERY measurement has it's weakness...
I do like the chart ..especially ALL that energy in the IR range..was that counted? Seems like it was (and a lot of wasted energy it is)
Needs clarification...........
to be clear, I'm not in any way stating that LED
's are as "efficient" as claimed..like a 30W LED replacing a 200W MH efficient for an example, and am pretty much in agreement that that has been one of the "mistakes".
Wishful thinking I guess..
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dz6t
New member
He is not using a par meter, also only some consumer grade low cost par meter have that issue.
The bottom line is that a 90w Kessil is not a replacement of a 250w metal halide lamp as their efficiency are similar.
shred5
Premium Member
http://www.apogeeinstruments.com/quantum/
Actually that had been fixed.
Apogee released the SQ/MQ-500 and the SQ-420 sensors which fix the issues and anyone with the older type can upgrade for a cost.
Not saying he didn't use a older one but letting people know the problem is fixed with newer models.
dkeller_nc
New member
Yep. I should re-emphasize that generally all SPS that I have except for acropora do quite well. And in the case of acropora not all colonies do poorly, just most of them. One possible difference is that I do not buy frags or named corals. They are all generally maricultured colonies that have done well for 4-8 weeks (sometimes much longer) under MH in a tank. So it may simply be that certain acropora strains that have been pre-selected in the aquarium hobby do well under any sort of light of sufficient intensity.
There is one company that I'm aware of that makes use of the lime green diodes - Nanobox. They get high marks for color rendition.
oreo57
Well-known member
Def. agreement there..As long as you take all those factors into consideration, you can figure out how much light you're really getting.
Get a PAR meter - you'll be happier
Using raw output is "almost" pointless.
An easy way to think about it is if you turned a MH upside down....Great light output but practically zero to the tank..
but one does need to start somewhere..
ONLY a in vivo measurement will be worth much of anything..
FYI.. a Kessil light distribution at 24" plot:
One can see where a decrease or parity in efficiency can still lead to a higher "effective" delivery..
http://www.myledlightingguide.com/led-versus-traditional-lamps-a-fight-between-unequals
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Wazzel
New member
It could be an acclimation issues. I only buy captive propagated frags and have had no issues growing anything. Definitely one of those things that make you scratch your head.
karimwassef
Active member
Thanks oreo. Glad we connect on this.
I have a separate thread where I measure the power and PAR of different multichip LEDs and I've come to the conclusion that DIY fixtures are not all equal. Different chips from different sources are significantly different from their "ratings"
Any design that isn't confirmed with a PAR measurement is a wate of time.
I wonder what the statistical distribution of PAR and wall-plug efficiency in commercial LED fixtures would look like vs. their promise.
What I'm getting at is that the variability in LED results across different users may be because LEDs can be individually different.
It's not that LEDs are worse than Halides... It's that your specific LEDs are inferior compared to my Halides or my LEDs. Someone else buying the same fixture may have gotten a better batch of chips.
Without measuring PAR, it's a crapshoot.
I have a separate thread where I measure the power and PAR of different multichip LEDs and I've come to the conclusion that DIY fixtures are not all equal. Different chips from different sources are significantly different from their "ratings"
Any design that isn't confirmed with a PAR measurement is a wate of time.
I wonder what the statistical distribution of PAR and wall-plug efficiency in commercial LED fixtures would look like vs. their promise.
What I'm getting at is that the variability in LED results across different users may be because LEDs can be individually different.
It's not that LEDs are worse than Halides... It's that your specific LEDs are inferior compared to my Halides or my LEDs. Someone else buying the same fixture may have gotten a better batch of chips.
Without measuring PAR, it's a crapshoot.
Wazzel
New member
I suspect the QC/QA is adequate enough that manufacturing difference should not come into play.
