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Old Bulbs = Algae?

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NaH2O

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Someone told me awhile back that old bulbs causing algae problems was a myth. So, since we have been on the topic recently of "myths", I wondered if this is true.

The standard argument is the spectrum shifts in an older bulb. Can someone point me to an actual study showing this is the case and relate it to algae growth? I would like to see where this came about, and have some proof. Why wouldn't a 6500K bulb tank have more algae than a 10,000K bulb tank that is shifting? It would make more sense to me that an algae growth would be experienced when NEW bulbs are put in. Better lighting with an already present nutrient problem = algae candy.
My understanding about algae is that nutrients are usually in abundance when there is growth. Perhaps, the myth is a result of tank husbandry going on the decline at the end of the bulbs life, creating a better environment for growth. Then, when the bulbs are figured to be the cause, not only do the bulbs get replaced, but there is also a general tank cleaning that makes the algae die back.

What do you think?
 

mojoreef

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Nikki what happens is that bulbs tend to shift to the red spectrum as they get old. It doesnt really cause algae but it does makes life happy for cyano. For me that is how I have always known when it is time to change the bulbs. I am not sure if thier is a study done on it but I will look


Mike
 

MikeS

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Any ideas as to what exactly causes the shift in spectrum? Is it the glass "yellowing" due to prolonged exposure to light, or in the case of flourescent bulbs esp. are the phosphors degrading, or a combination of things?

MikeS
 

mojoreef

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That sounds like a Boomer question to me Mike. I believe its to do with the temperature fading.



Mike
 

NaH2O

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mojoreef said:
Nikki what happens is that bulbs tend to shift to the red spectrum as they get old. It doesnt really cause algae but it does makes life happy for cyano.
Is there a depth in the ocean when the red spectrum no longer penetrates, and if so, does cyano not grow there?
 

MikeS

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Red light get filtered out pretty quickly....

On red light causing algae blooms, I agree with mojo....the warmer K light may help fuel a cyano/algae problem, but isn't the cause...other factors play a much more improtant role in the development of cyano/algae...

MikeS
 

mojoreef

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Cyano grows and is in most living things Nikki, with or with out light. You have to look at it as a enviromental thing. Our tanks are always tettering on nutrient loaded, one little more of a skew and the enviroment is good for so something that it was not good for prior.


Mike
 

NaH2O

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I found a thread in which Jerel points out that old bulbs don't cause algae issues. He did put up a deep water picture showing hair and cyano. I will post it below. I was just curious as to any studies showing that it is indeed the bulbs and not excess nutrients (going back to Alberto's hearsay thread). Mike, I understand and agree with your point about teetering on a nutrient overload, but then that (excess nutrients) would be the cause and not the old bulb? I'm really lost on this whole thing.

 

MikeS

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NaH2O said:
Mike, I understand and agree with your point about teetering on a nutrient overload, but then that (excess nutrients) would be the cause and not the old bulb? I'm really lost on this whole thing.
Exactly....the warmer K may be a bit more condusive to cyano growth, but it's not the actual cause of said growth. The cyano needs nutrients first and foremost. I would say the only factor that the warmer K bulb would have on cyano would be to perhaps worsen an existing cyano problem, by providing it with a spectrum more to its liking, so to speak.

MikeS
 

Scooterman

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Many things can cause a K shift. An important factor is internal bulb pressure and temperature. The pressure and heat are both a function of the rise in Ar (Argon ) gas pressure and Hg (Mercury) vapor pressure. OD a lamp can make both of these rise. Increased bulb pressure increases output and makes the lamp produce more lumens / watt. Ar, in a fluor lamps, does not add light as it does in a MV, MH or HPS. It purpose is to make the lamp have more output with less wattage. Fluor's are LID (Low Intensity Discharge) Lamps and do not produce enough energy to ionize the Argon gas. If it did, it would change the K value, as the Ar is producing visible light. Almost all the light in a fluor produced is UV, where its wavelength is lengthened by the phosphors.

OD can cause a deterioration of the phosphor coating. The filaments also break down more quickly and leave a emissive material on the inner surface of the bulb. Both of these will cause a shift in K and light output. You guys need to remember that light bulb data is based on std tests. For example, x type HO lamp running at an ambient room temp of 60 F will produce 100 % output. Taking that same lamp and increasing it to 80 F will reduce the output to almost 90 %. HO's actual produce more light at lower ambient room temp than NO's. It takes more UV energy to drive some phosphors than others, where other phosphors require less UV energy. This shift in temp or pressure changes the energy output of mercury. This and the above change the output and K.
From Boomer
 

mojoreef

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Mike, I understand and agree with your point about teetering on a nutrient overload, but then that (excess nutrients) would be the cause and not the old bulb?
Well if the enviroment was tettering but still not skewed enough to cause cyano then no it wouldnt be the nutrients. As in if the light shift was the factor that finaly skewed the enviroment over.

Ok let me see if I can clear it up a bit. The outer part of the cell contains a photosynthetic algal mechanism and the ensuing pigments. Types of lighting used influence the growth of these alga, pigments with in the alga absorb certain wavelengths of light. The one that we are probably most concerned with, the red slime algae, have a great deal of phycoerythrins. Its absorption level is optimized at 555-564 nm (manometer) wavelength (red). Now thier are other pigments and they are controled by the available light above them. which ever light it is will determine the which one will dominate. All the pigments present in cyano are called Phycobiliproteins. These protiens Harvest the light waves in the PSII system (photosynthisisII) cycle. Light wavelength energy now trapped is transmitted to the PS I system and its Chlorophyll (mostly of type a). And from thier it becomes the standard cycle you know about.

Here are some studies for ya so we dont think its a myth. :p

http://morgan.ucs.mun.ca/~x52lcw/
http://www.blackwell-synergy.com/links/doi/10.1046/j.1529-8817.2003.02116.x
http://jxb.oupjournals.org/cgi/content/abstract/56/411/389
http://biology.kenyon.edu/Microbial_Biorealm/bacteria/synechococcus/synechococcus.htm
http://www-micro.msb.le.ac.uk/video/Cyanobacteria.html
http://www.bmb.psu.edu/faculty/bryant/lab/synechococcus7002genome/
http://www.upsc.nu/Default.asp?pageid=751&path=756,763,881,782
http://www.biologie.hu-berlin.de/~pflbch/phycobilisomes.html
http://tres.blki.hu/BLRI/munkatarsak/AKovacs_eng.htm
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=12659496&dopt=Abstract

Anyway cyano still needs N and/or some different types of nutrients but lighting temp does effect its growth.


Mike
 

MikeS

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mojoreef said:
Well if the enviroment was tettering but still not skewed enough to cause cyano then no it wouldnt be the nutrients. As in if the light shift was the factor that finaly skewed the enviroment over.

Mike
The proverbial "straw that breaks the camel's back"....
But the other conditions have to be in place, right...ie you wouldn't see this in a tank that doesn't have a high enough nutrient load to cause a cyano bloom...

ok, here's a question along those same lines...how much of a kelvin shift are we looking at here? I mean obviously a 10000K bulb isn't going to shift down to say 6000K, right? Or could it given enough time? And is there a particular kelvin rating that increases the likelyhood of a bloom (given the proper nutrient condtions in the tank), or is simply the shift in kelvin away from what a particular tank is normally adapted to enough to get the ball rolling?

MikeS
 

Scooterman

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How about a point when a lamp starts shifting, it drops off in PAR, maybe the curve is larger than the kelvin curve of drop off?
 

mojoreef

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Mike I edited my post to show some studies, that and my post should answer your questions. Take a peek and let me know if you need more.


Mike
 

MikeS

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ok...I see....so it has more to do with a particular wavelength of light than color temperature, correct? In that case, when we refer to a spectral shift in our lights, it has more to do with the output of the light spiking at a particular wavelength, rather than a shift in kelvins?

MikeS
 

MikeS

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Lots of good info up there, Mojo....hey I gotta ask...EXACTLY how long is your browser's "Bookmark" page? :?: :D Man, you can just throw down those links in large quantities on just about any subject... :lol:

Ok, so does the bulb begin to develop color spikes in the red wavelength range, or do the color spikes in the blue wavelength range simply lose intensity allowing existing red spikes to become a larger part of the total spectrum of the bulb? And either way, this would also shift the bulb towards a warmer kelvin output, wouldn't it?

MikeS
 

mojoreef

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Lots of good info up there, Mojo....hey I gotta ask...EXACTLY how long is your browser's "Bookmark" page?
I dont have them all in the fav section, but I have a little over 22000

A little quick note here. Cyano still needs nutrients, mostly N but other stuff like mag, iron, P and so on will also work. It also does not need light, although light will greatly increase it. Cyano's are amongst the most diverse in the world and with out them we would not exsist. In our reef tank we will always have them, if your tank is pretty good with nutrients you will not notice them as the alga portion of them doesnt take hold. A shift in the lighting spectrum to red will skew things to the algal portion of cyano and cause it to bloom or become present.

Ok, so does the bulb begin to develop color spikes in the red wavelength range, or do the color spikes in the blue wavelength range simply lose intensity allowing existing red spikes to become a larger part of the total spectrum of the bulb?
Again this is more Boomers world then mine, but from memory the whole spectrum of the bulb moves forward into the red zone.
And either way, this would also shift the bulb towards a warmer kelvin output, wouldn't it?
Cooler I would say Mike.

Mike
 

MikeS

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22,000? Holy Cow mojo, how do ya keep them all straight? :eek: :lol:

Cyano is also about the oldest lifeform on earth that we are aware of, right? I think I remember hearing about fossil records billions of years old containing cyanobacteria...

On the Kelvin rating...sorry, I used "warmer" to refer to a more yellow/red light, Blue as a "colder" light....I guess that would be a confusing way for me to express that, as the more red it gets, the lower the Kelvin rating...sorry, I'll try to avoid that habit... :D

MikeS
 
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