14k mh bulb - follow up

[Glenn E King]

Excellent answers thank you!

Now on to the bonus round...
When you buzz in Identify Your School and Remember to phrase your answer in the form of a question.

If I am interested in coral growth do I want a fuller spectrum vs the spike in the Phoenix?

 

[inverted]

What is, well, I have a shoal of Anthias, not really a school though. Does that count? Also, what is better, that's a tough one

You will get more PAR from yellow light, as it takes less energy to produce yellow light than blue light. More blue light penetrates the water though and corals tend to be better adapted to blue though. However, corals can typically adapt to lighting, so, having more yellow, or less blue, may be a wash as they use blue better, but you can get more yellow from the same wattage. It's tough to tell really what's best. Some corals, such as shallow water corals though, may be better adapted to specific wavelengths. So, having a wider range may be better in that case. So, I'd say there may be a slight preference for the wider spectrum, but it will vary by coral and I'm not sure it is enough to really notice in many situations as light is only one of many factors. Also, some corals may not have protective pigments to protect them from excessive light at certain wavelengths. Such as a deepwater coral. So, having a more full spectrum could be bad for some corals too. Personally, I still prefer the bluer look.

You may find this article useful:
http://www.advancedaquarist.com/2008/12/aafeature1

 

[me2003]

My Jeopardy questions.


Did the paper Evaluation of artificial light regimes and substrate types for aquaria
propagation of the staghorn coral Acropora solitaryensis
by Thomas A. Schlacher a,⁎, Jane Stark a, Andreas B.P. Fischer b state

In our experiment,growth and survival of A. solitaryensis was higher under
blue light (i.e. 14000 and 20000 Kelvin) than under red
(i.e. 5500 and 10000 Kelvin) light?

Does the type of coral matter?

What is blue?

Do metal halides shift in color?

 

[inverted]

My Jeopardy questions.


Did the paper Evaluation of artificial light regimes and substrate types for aquaria
propagation of the staghorn coral Acropora solitaryensis
by Thomas A. Schlacher a,⁎, Jane Stark a, Andreas B.P. Fischer b state

In our experiment,growth and survival of A. solitaryensis was higher under
blue light (i.e. 14000 and 20000 Kelvin) than under red
(i.e. 5500 and 10000 Kelvin) light?

Good questions. I do not have access to that journal apparently, so, my answers are limited...

Does the type of coral matter?

Likely, if we look at coral pigmentation as an indicator of preferred environment, then yes. Dana, for example, summarizes many different pigments here: http://www.advancedaquarist.com/2009/1/aafeature1 We can see that there is considerable variation by coral.

What is blue?

roughly 440–490 nm. (hehe, well, i don't have access to the article as mentioned, so, I'll stick with a smartass comment The real answer, regarding the article, I believe will be the respective blue light produced by each bulb tested. This is certainly not a great metric though, and I suspect much confounding, but that depends on the methods)

Do metal halides shift in color?

Which one? I would tend to think there may be some shift, as discussed here:
http://www.personal.psu.edu/sbj4/aquarium/articles/MetalHalideLamps2.htm

 

[stingythingy45]

I'll give you first hand experience.
I have run Ushio 14 K for 2 bulb changes.
And recently have run Phoenix 14 K.
Coral grows much slower under the very blue phoenix bulbs.
I plan to go back to Ushio 14K when I order tomorrow.
Do you have a year to wait for my results?

 

[inverted]

I'll give you first hand experience.
I have run Ushio 14 K for 2 bulb changes.
And recently have run Phoenix 14 K.
Coral grows much slower under the very blue phoenix bulbs.
I plan to go back to Ushio 14K when I order tomorrow.
Do you have a year to wait for my results?

I'll be waiting for results! I'd have to also ask though, which corals? Saying "corals" implies all of your corals, is this true?



Also, to bring up one important point, corals don't use light, their symbiont do. They then get energy in the form of organic carbon from the symbiont. They still need other nutrients to use this carbon (for example see Falkowski et al. 1984)
"Light and bioenergetics of a symbiotic coral. Bioscience".

Also, zooxanthellae can only use a certain amount of light, perhaps less than one might expect (for example see: http://www.advancedaquarist.com/2007/3/aafeature1).

A recent review article Osinga et al. (2011) "The Biology and Economics of Coral Growth" lists 4 reasons corals may grow slow as a result of light.
"1) insufficient production of photosynthates"
"2) insufficient
translocation of photosynthates, for example after enrichment
of seawater with inorganic nutrients"
"3)a decrease of the internal pH due to lower photosynthesis,
leading to less favorable conditions for calcification"
4) photoinibition

Of the 4, #2, as mentioned deals with insuficient food/nutrients to use the light. And #4, deals with too much light. #3 could be a result of too little light, but could be other factors, such as bleaching for example. #1 deals with too little light.

So, just because a light is or isn't more photosynthetically productive, doesn't mean it will necessarily effect growth of the coral. For example, I could hypothesize that if a lamp radiates too much usable light, the coral may photoinhibit and growth could decline. If I then switch to a lamp that uses the same power, but radiates more light in less-usable wavelengths, perhapse growth will increase, because the coral will no longer be photoinhibited. This doesn't say that one light is better than the other, but rather that there was too much light with one. Perhaps, in this case, the same results could be obtained by reducing the intensity of the first light...

 

[me2003]

"Good questions. I do not have access to that journal apparently, so, my answers are limited..."
http://www.advancedaquarist.com/2008/12/aafeature1 article you referenced discusses it
in a lot of detail. Access is a major issue with journal articles. I think some libraries allow online access if you are a member. I would post a copy but I might get arrested and indefinitely detained by the copyright infringement internet police.

 

[jimrawr]

From my experience the Ushio 14k bulbs grew faster than the Radium 20k

 

[Aquaman_68]

yeah & the iwasaki 15 k 175 watt grows better than them all....hands down....After that....if ur looking primarily at growth...iwasaki 65K I beleive grows stoneys the quickest...(but the color is awful) sanjay ran the iwasaki "eye" 15k 175 watt thru the par tests....it had par values equal to a 250 watt !!!!

 

[stingythingy45]

I should probably point out that I ran both the Ushio and Phoenix on a Bluewave 7 mag. ballast.
I love the look of the Phoenix bulb,nice cool blue color,very pleasing to the eye.Didn't even need the two 55 watt T5 actinics for color enhancement.
But,by far,the sps and many other lps corals grew much faster under the 14k Ushio.JMO

 

[inverted]

"Good questions. I do not have access to that journal apparently, so, my answers are limited..."
http://www.advancedaquarist.com/2008/12/aafeature1 article you referenced discusses it
in a lot of detail. Access is a major issue with journal articles. I think some libraries allow online access if you are a member. I would post a copy but I might get arrested and indefinitely detained by the copyright infringement internet police.

I take it you mean there isn't much more detail in the original article? Usually we have access to most journals, especially Springer journals. This journal is just too specialized, or obscure or something I guess...

I should probably point out that I ran both the Ushio and Phoenix on a Bluewave 7 mag. ballast.
I love the look of the Phoenix bulb,nice cool blue color,very pleasing to the eye.Didn't even need the two 55 watt T5 actinics for color enhancement.
But,by far,the sps and many other lps corals grew much faster under the 14k Ushio.JMO

I agree, shallow water corals, such as SPS may benefit from the extra spectrum. Long term though, it shouldn't matter much, as many corals, especially SPS IMO, are quite capable of photoadaptation. So, as long as you have enough light and acclimate the corals to the light, you should see less of a difference in growth over time. Actually, in that case, it is my experience that going back to wider band lighting can slow growth until the coral re-acclimates to the wider band lighting. So, I think it is more of an acclimation issue and believe this makes sense based on the available data.

That said though, lower K bulbs replicate the wide spectrum of the sun better at shallow depths. So, a lot of wholesalers use low K bulbs because they do better initially without the acclimation. So, if you use a low K bulb you could see more growth initial. The Ushio though, is more like a 10K bulb, but with less PAR. So, if you really want initial growth, without acclimation, you could go with a 10K. Heck I had a 10K XM laying around that I never used. So, I just plugged it in and I was getting abut twice the PAR of of my 250W 140000K Phoenix! And what's more impressive, is that this is at 250W electric ballast mode, and I was running the phoenix on HQI mode, which runs at more like 300W! Of course, the yellow color sort of made me feel like vomiting LOL.

 

[mannix]

On the acclimation part of this where does he get his corals and how long have they been there. Secondly how long will it take the corals to adapt. It seems it would be best to match where he bought them from if they adapt rather quickly or where they are from originaly if they take a long time to adapt.