Radium metal halide bulbs will not be produced anymore!

[Backreefing]

I don’t like the yellow look of 6500K , but I would bet they grow coral like weeds .

 

[Nonya]

I don’t like the yellow look of 6500K , but I would bet they grow coral like weeds

Not so much. We used to insist that the color temperature closest to the noon sun must be the best. Much experimentation has been done in the past 15 years to show the benefits of a more blue-violet spectrum on coral photosynthesis. I found an old article by Dana Riddle here: https://reefs.com/magazine/the-best-lamp-is/ which showed a better growth rate at higher Kelvin temps, with the exception of the 10,000K bulb used. He postulated that the amount of red light from the 10,000K bulb could be a factor in hindering coral growth. Still, the bulk of reefers nowadays seem to favor the bluer hues for growth, health, and pigmentation.

 

[A. grandis]

Not so much. We used to insist that the color temperature closest to the noon sun must be the best. Much experimentation has been done in the past 15 years to show the benefits of a more blue-violet spectrum on coral photosynthesis. I found an old article by Dana Riddle here: https://reefs.com/magazine/the-best-lamp-is/ which showed a better growth rate at higher Kelvin temps, with the exception of the 10,000K bulb used. He postulated that the amount of red light from the 10,000K bulb could be a factor in hindering coral growth. Still, the bulk of reefers nowadays seem to favor the bluer hues for growth, health, and pigmentation.

There is a tendency to assume that the blue light for the photosynthesis is everything we need for the coral metabolism to reflect in optimal growth, pigment formation and general health, while the fact is that under lower kelvin bulbs we practically notice faster growth and more diversity of pigment formation. In the ocean is the same thing. Coral farms under the sun have the very best corals produced!
Every coral will respond to light in a different way and each species should be taken in consideration as we know. That is another aspect many tend to ignore while comparing light for corals. Practically we will see faster growth in the majority of the shallow water corals, anemones and zoanthids when under lower kelvin bulbs, no doubt about that. The intensity and duration needs to be taken in consideration for each particular comparison and proper application.
The paper suggested is a great example of an experiment using isolated wavelength to prove a point (see also Riddle, D., 2004. PAM fluorometer experiments: Part I. Effects of metal halide lamp spectral qualities on zooxanthellae photosynthesis in photoacclimated Fungia corals: The red light theory. Part II. Effects of water motion on zooxanthellae photosynthesis.)
In reality it proves that red light, when used alone, is in fact way too effective for photosynthesis, and excess of oxidation occurs because of the application. Photoinhibition happened due to the strong emission of red light alone in a short distance. That doesn't happen in the aquarium with adequate distribution using the right wattage of halide. If it normally doesn't occur when using a 6500K 250W halide at 12 inches from a coral, with well distributed light from a parabolic reflector, it proves that the application is what matters. If doesn't happen in 12" deep tide pools under tropical sunlight over those shallow water coral species found in those pools, it shouldn't be a problem.
Dana used 6500K halides over his coral farm in the 90's because he knew they were the best bulbs to grow those corals. The best coral farmers will tell you the same today. The best bulb to grow corals is the 6500K metal halide. Or the sun.

 

[jda]

More blue in 5500/6500k bulbs than in led panels. Just more of other colors too.

 

[A. grandis]

Yup! that's another truth many tend to ignore.

 

[Cichlid Dad]

Plantmax 600 Watt Pulse Start Metal Halide 10K Lamp - 1 Pack https://a.co/d/9X5EOp4

I've used 1000 watt bulbs with a 600 watt ballast when I was growing indoors. I don't know if it works the same way with reef tank ballast I see talked about on R2R. Maybe someone will know. But these are available now

 

[Mikeltee]

I still prefer MH but due to a variety of issues mostly related to electric and heat I went to Kessils then G5's. If nothing else maybe this will finally end the decade+ long argument of MH vs. LED . On a positive note, I was talking to Champion at RAP and it was mentioned they still have a good supply of MH bulbs which I got the impression they were trying to get rid of.

I ran MH for 10 years. Once I went to LED the problems started.

 

[Nonya]

There is a tendency to assume that the blue light for the photosynthesis is everything we need for the coral metabolism to reflect in optimal growth, pigment formation and general health, while the fact is that under lower kelvin bulbs we practically notice faster growth and more diversity of pigment formation. In the ocean is the same thing. Coral farms under the sun have the very best corals produced!
Every coral will respond to light in a different way and each species should be taken in consideration as we know. That is another aspect many tend to ignore while comparing light for corals. Practically we will see faster growth in the majority of the shallow water corals, anemones and zoanthids when under lower kelvin bulbs, no doubt about that. The intensity and duration needs to be taken in consideration for each particular comparison and proper application.
The paper suggested is a great example of an experiment using isolated wavelength to prove a point (see also Riddle, D., 2004. PAM fluorometer experiments: Part I. Effects of metal halide lamp spectral qualities on zooxanthellae photosynthesis in photoacclimated Fungia corals: The red light theory. Part II. Effects of water motion on zooxanthellae photosynthesis.)
In reality it proves that red light, when used alone, is in fact way too effective for photosynthesis, and excess of oxidation occurs because of the application. Photoinhibition happened due to the strong emission of red light alone in a short distance. That doesn't happen in the aquarium with adequate distribution using the right wattage of halide. If it normally doesn't occur when using a 6500K 250W halide at 12 inches from a coral, with well distributed light from a parabolic reflector, it proves that the application is what matters. If doesn't happen in 12" deep tide pools under tropical sunlight over those shallow water coral species found in those pools, it shouldn't be a problem.
Dana used 6500K halides over his coral farm in the 90's because he knew they were the best bulbs to grow those corals. The best coral farmers will tell you the same today. The best bulb to grow corals is the 6500K metal halide. Or the sun.

Too many unsupported claims to address. I'll just address the last paragraph. I seriously doubt that higher Kelvin bulbs (above 10,000K) were available for use in the 90's. Second, Dana didn't have a coral farm in Hawaii. Third, name the "best coral farmers" who are using low Kelvin lighting today. I know that you aren't growing stony corals in Hawaii, so what personal experience can you point to? I've use halides ranging from very low Kelvin through 20,000K. I had much better coloration with the higher Kelvin bulbs. The low Kelvin bulbs promoted algae growth. Right now I'm growing beautiful corals under nothing but blue, royal blue, and violet/UV light.

Regardless, your opening post that Radiums are going away supports the fact that halides are about to go the way of the dinosaurs. If 6,500K is best, I'm assuming the high Kelvin Radiums should have no detrimental effect on the hobby.

 

[jda]

Riddle has said that they had massive growth under 6500k when he was a coral farmer - throwing in that the location is wrong in Hawaii is distracting and makes a childish type of counterpoint by ignoring the actual purpose. When I started reefing in 1992, you could buy MH out of the back of TFH Magazine with 5500k or 6500k bulbs that came in the kit - fact. Also, Adam at Battlecorals uses 6500k bulbs at least until his stock runs out... he has posted about this a lot.

I don't care to argue much about what is better anymore. Some people just aren't talented enough of hobbyists to get good colors without heavy blue light, and some don't care. It doesn't matter to me since they are happy. Discounting what the more talented can do with the tools is pretty dumb, though.

If you want to challenge my personal experience, I have 30 (or so) years of posts on a few different boards and a build thread. If people can do better, then I am happy to hear about it. I have grown frags to wall-to-wall dinner plate colonies many times and think that I have a pretty good idea about how to do things.

 

[Nonya]

Riddle has said that they had massive growth under 6500k when he was a coral farmer

I'd like to see where he said that. Coral farming in Hawaii is forbidden.

 

[jda]

Are you serious? He has not always lived in Hawaii. He doesn't live there now either. He has bios online that you can find. If you don't want to do your homework, then I/we can educate you, but how about you lay off people for making similar mistakes and focus on the point at hand?

 

[Nonya]

When I started reefing in 1992, you could buy MH out of the back of TFH Magazine with 5500k or 6500k bulbs that came in the kit - fact. Also, Adam at Battlecorals uses 6500k bulbs at least until his stock runs out... he has posted about this a lot.

You have me there. I've only been at it since around 1998. I've been through the complete spectrum of lighting--PC fluorescents, daylight halides, VHO actinics, high Kelvin halides, was among the first to DIY LEDs, experimented with pure blues to prove a single, narrow region of blue could successfully grow SPS, and have decided, based on my personal experience, that the blue-violet spectrum has way too many benefits, with no discernable downside. I only turn on whites when I need to clean the glass.

 

[Nonya]

Are you serious? He has not always lived in Hawaii. He doesn't live there now either. He has bios online that you can find. If you don't want to do your homework, then I/we can educate you, but how about you lay off people for making similar mistakes and focus on the point at hand?

Enlighten me.

 

[Reefering1]

I only turn on whites when I need to clean the glass.

Or see something inside, right

 

[Nonya]

Or see something inside, right

Maybe if I dropped a magnet or scraper. Seriously, the blue-violet region is all I ever use. It wasn't too bad when I was using 14,000K halides, but the pop is even better now.

 

[Nonya]

...focus on the point at hand?

The point at hand is that a major supplier of high Kelvin halides is ceasing production. Fortunately, there are alternatives in T-5 and LED.

 

[jda]

If you could not grow and color coral well with 6500k halides, then you were not talented enough. You might not like the way that some of them look, but for growth and rendering actual color, they are almost like a cheat code. They cannot make ugly corals look good. You should have had wonderful yellows, pink and blues under 6500k lights. The best looking coral are still from full daylight and then blued-up to your liking - ask anybody who has gotten a BattleBox... the color fades in time without the daylight, but they look great at first.

Either you did not actually use 6500k bulbs, or you did not have the skill to get good results. Nobody who has had both ever had said that they sucked and did not work... only that they moved on for other reasons like looks or heat or something. They were hot and they did drive changes to future generations of MH bulbs which are considerably less hot (except for Radium, IME).

I personally found 14k to be a good blend of output and color along with the crisp white look that is neither yellow nor windex. I do use 6500k t5 in some frag tanks and the colors and growth in there are amazing too... these frags shine when you put them under 14k even more than the frags grown under 14k, but I live with that for the crisp white look that I described above.

 

[Nonya]

You have me there. I've only been at it since around 1998. I've been through the complete spectrum of lighting--PC fluorescents, daylight halides, VHO actinics, high Kelvin halides, was among the first to DIY LEDs, experimented with pure blues to prove a single, narrow region of blue could successfully grow SPS, and have decided, based on my personal experience, that the blue-violet spectrum has way too many benefits, with no discernable downside. I only turn on whites when I need to clean the glass.

I almost forgot--I tried plasma for a while. Not energy efficient. It ended up being a little faddish.

 

[Nonya]

If you could not grow and color coral well with 6500k halides, then you were not talented enough. You might not like the way that some of them look, but for growth and rendering actual color, they are almost like a cheat code. They cannot make ugly corals look good. You should have had wonderful yellows, pink and blues under 6500k lights. The best looking coral are still from full daylight and then blued-up to your liking - ask anybody who has gotten a BattleBox... the color fades in time without the daylight, but they look great at first.

Either you did not actually use 6500k bulbs, or you did not have the skill to get good results. Nobody who has had both ever had said that they sucked and did not work... only that they moved on for other reasons like looks or heat or something. They were hot and they did drive changes to future generations of MH bulbs which are considerably less hot (except for Radium, IME).

I personally found 14k to be a good blend of output and color along with the crisp white look that is neither yellow nor windex. I do use 6500k t5 in some frag tanks and the colors and growth in there are amazing too... these frags shine when you put them under 14k even more than the frags grown under 14k, but I live with that for the crisp white look that I described above.

If you could not grow and color coral well with 6500k halides, then you were not talented enough.

Either you did not actually use 6500k bulbs, or you did not have the skill to get good results.

Wow, kind of prickly.
You should read my previous posts. I've definitely used 6,500K halides. My corals grew just fine. I just didn't like the appearance, and I had suspicions that a bluer spectrum might be closer to the natural environment in which most corals grow in the wild. 14,000K was better, but still not to my liking. I've moved on from old school, energy inefficient, fixed spectrum technology, which led to the ability of experimenting with variations in spectra and intensity. After years of experimentation, I've come to realize that blue-violet provides excellent pigmentation, coral growth, and most of all, visual appeal--in my personal experience and personal preference.

 

[jda]

I am happy if you are happy. Probably not a good idea to post some of what you did then since the folks who use these bulbs are plenty happy too. There are just too many proven issues with the posts -like inefficient was an argument for 10 years ago, not now... it has been pretty well proven that you don't save any electricity with LEDs over MH unless people just choose poorly to begin with (400w MH and 4x 100x VHOs over a 40 breeder when 2x 175w MH would have been fine). Old-school dig is also a problem since there has been more actual improvement to MH since LEDs last had a significant change - multicolored diodes are older than the dual arc and less heat current MH bulbs also with very efficient ballasts. Going the way of the dinosaur also sounds really dumb, IMO... there are still plenty of places that make MH bulbs and you have not actually been reading this thread if you think that the story of Radium 20k is over. VHOs are still being made and their exitinction was predicted about 20 years ago. Lastly, it has been shown over and over that nearly everything that we have in our tanks is collected on one breath at a spectrum of about 6500k - some corals grow deeper, but that is not where they are collected since the equipment needed to go deeper is used to collect fish which can bring hundreds of dollars at a wholesaler or transshipper instead of a few pennies. There are people who will take you out of collect corals in the triangle and you get a bag, mask and some sort of cutting tool.

Of course, preference is the right answer and people will likely care about this. The rest seems petty, biased and uneducated.