14k or 20k halide
- Thread starter jasonseaman
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Nope. IE9 on a machine running Windows7.
OK. I found the plots by searching online.
And the plots back up what I stated.
I agree that the actual spectrum profiles look very different, as expected.
But what I said was that MH bulbs basically put out the same wavelengths but with different intensities at different wavelengths.
Both the Iwasaki 6500 and the Radium 20k are putting out some intensity at all wavelengths from about 340 up to 800.
Different intensities, but neither bulb (nor any other of the bulbs in Sanjay's plots) dropped to zero intensity for any range of wavelengths between about 340 and 800.
So, the earlier statement that a bulb could be both a 14k and a 20k bulb is really meaningless, since even the 6500 has some intensity at the bluer spectrums.
I don't think we are looking at the same things. The spectral plots are in no way similar, and represent drastically different bulbs. The peak are in different places, the size of the peaks are different as well, and as you can see almost all of the output from the 20k is in the blue area of the spectrum, with it registering almost 0 at higher wavelengths. That is what makes a one bulb different from the other. Saying that they are all the same because they all "produce light in the 380-800 range", or the VISIBLE SPECTRUM, is like saying a 20k MH is no different from a small compact fluorescent bulb that I use to light my house because they both produce light along the visible spectrum. That is a silly comparrison. All bulbs produce light over the visible spectrum, it just a matter of where the light is the most intense and least intense, and that makes all the difference between one bulb to another.
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Didn't even try to imply they were similar spectrum plots. Simply said that both bulbs produced some intensity at all wavelengths.
Or if it is easier to understand, I said that they put out basically the same wavelengths but at different intensities at individual wavelengths for each bulb.
The 6500 bulb is still putting out light at 450nm, just not as much as a new 20k radium. (Interesting that both bulbs have a bit of a peak at about 545nm).
I do not see anyplace where either bulb puts out zero intensity at the range of wavelengths shown in the graph.
That is the nature of MH bulbs - they put out a wide range of wavelengths. Unlike LED's
By the way - do compact flourescents put out light at all wavelengths in nthe visible spectrum? I haven't looked at spectral plots for that type of bulb.
Or if it is easier to understand, I said that they put out basically the same wavelengths but at different intensities at individual wavelengths for each bulb.
The 6500 bulb is still putting out light at 450nm, just not as much as a new 20k radium. (Interesting that both bulbs have a bit of a peak at about 545nm).
I do not see anyplace where either bulb puts out zero intensity at the range of wavelengths shown in the graph.
That is the nature of MH bulbs - they put out a wide range of wavelengths. Unlike LED's
By the way - do compact flourescents put out light at all wavelengths in nthe visible spectrum? I haven't looked at spectral plots for that type of bulb.
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So you are going to argue then there is a meaningful difference between a spectral irradiance of 0 and one of .025? That is so small that it could easily be attributed to differences in how they measure, and where they set the "0" point at. I have used a very high end spectrometer before, and you get radiance levels measured at all points. Its just a matter of what you subjectively set your 0 point at.
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Actually, I am trying to argue that saying a bulb is both 14k and 20k is nonsense, as even a 6500 bulb puts out some light in those colour ranges.
And I beleive Sanjay's plots were zeroed at about 300nm. So I assume the positive values he showed at 600-800nm were probably reliable measurements.
And I beleive Sanjay's plots were zeroed at about 300nm. So I assume the positive values he showed at 600-800nm were probably reliable measurements.
And I am saying that most light bulbs(with the exception of colored leds and some t5's) put out light in the same wavelengths of light. (Incandescent: http://www1.assumption.edu/users/bniece/spectra/HiResolution/Wg.pdf) cfl: http://www1.assumption.edu/users/bniece/spectra/HiResolution/FLg.pdf t5: http://www.reefgeek.com/reefgeek/8703/giesemann_aquablue_plus.jpg). So saying that "both bulbs produced some intensity at all wavelengths" is such a broad general description that it could be said of many bulb, and doesn't mean that the two are alike. It is where the bulk of the intensity is that makes all the difference, and not where a tiny fraction is (i.e. the .025 irradiance).
tat2z_21
tat2z_21
I feel like this is that Snapple Tea commercial, "Lemon", "Tea", no LEmon, no Tea. I am just waiting for someone to break out is a spectral plot inflatable suit and start wrestling.
chickenofthesea
Well-known member
Just go LED then you won't have to worry about replacing bulbs, and most LED lighting setups have controls to adjust spectrum and intensity. Problem solved! LOL
tat2z_21
tat2z_21
Well most of your LED do not have the ability to adjust spectrums, just color temp. Your typical LED has only blue and white LEDs which the white covers a little of the spectrum but mainly spikes at 450 to 480. So unless you add other colors into the mix your spectrum is still limited. However you can adjust the intensity and color of the tank.
tat2z_21
tat2z_21
I agree that you have the right to "Geek" out, but I feel that you guys are arguing the same thing from different outlooks. Hope the geekiness works out for ya
Where some see arguing, I see a discussion. I always learn something whenever I debate someone on this forum. I don't take any of it personally, and I hope they don't either.
colin779
Well-known member
The person that said a bulb that is a 14k and a 20k may have been talking about a dual arc bulb which literally has two tubes in it that fire alternately. One cycle the 14k lights, the next cycle the 20k lights, and it repeats that way =)
Twin Arc |Dual-Arc| 175 W watt Aquarium Reef 14K / 20K Metal Halide Bulb Mogul | eBay
There is a difference between a 14k and 20k bulb though, depending on the manufacturer the color difference may not be super apparent as some 14k's are substantially more blue then they should be (like a phoenix bulb). A true 20k and a true 14k should visually be very different with the 14k being the more intense of the two.
Twin Arc |Dual-Arc| 175 W watt Aquarium Reef 14K / 20K Metal Halide Bulb Mogul | eBay
There is a difference between a 14k and 20k bulb though, depending on the manufacturer the color difference may not be super apparent as some 14k's are substantially more blue then they should be (like a phoenix bulb). A true 20k and a true 14k should visually be very different with the 14k being the more intense of the two.
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NC2WA
Well-known member
let's call it good heated banter... LOL..
I would just send your question to the master: Sanjay, see his reply, and then call it good. But that is me
I would just send your question to the master: Sanjay, see his reply, and then call it good. But that is me
chickenofthesea
Well-known member
tat2z_21 you are right about what color LED's most companies use for their fixtures. I apologize for using the word "spectrum" when I meant color temp. Some LED manufactures do make other colors than blue and white. Rapid for instance (not that I am promoting this company, just using as an example) makes two different blues, three different whites, green, red and violet leds. They also sell dim able drivers to adjust intensity. Aqua Illumination (and many other manufactures) sells fixtures were the blues and whites can be adjust individually for intensity and color temp. I know for a fact that people are growing SPS under those SOL fixtures. I am not saying that LED's are for everyone but they do posses a lot of advantages over MH. They run cooler, they last way longer, fixtures can be adjustable for color temp and intensity and they don't cost that much anymore to build or buy compared the the MH set-ups people are pointing out in this thread. The only real advantage to MH in my opinion these days is if you have a ridiculously deep tank, which most people don't, and that you can pick up and older used set-up for super cheap (but you still have to buy the ridiculous costing bulb every 6+ months) and even then ecoxotic has the cannon LED pendant which has eliminated the issue with depth. Just Sayin', think about it.
tat2z_21
tat2z_21
I completely get what your saying I think LED is definitely the way to go. And have built several LED systems. Love them. I love the control, and the intensity. So I am a BIG fan of the LED's.
chickenofthesea
Well-known member
Hey tat2z_21, which LED's do you use and in what color combination?
tat2z_21
tat2z_21
Well since my tank is down and lights haev been sold, I do not have any right now. But I did have over my 180 3 sets of lights over the tank and this was the combo per unit
1x 100w multi chip LED 20k
6x 3w Phillips Luxeon Nw
12x 3w Phillips Luxeon RB
1x Osram Hyper red
All ran at 35% and looked amazing. I originally had 3x250w Phoenix 14k and 2x110 Super actinic VHO's, changing over cut my electricity down by 70 dollars a month
1x 100w multi chip LED 20k
6x 3w Phillips Luxeon Nw
12x 3w Phillips Luxeon RB
1x Osram Hyper red
All ran at 35% and looked amazing. I originally had 3x250w Phoenix 14k and 2x110 Super actinic VHO's, changing over cut my electricity down by 70 dollars a month
