Old light algae bloom fact or fiction?

[Ron Reefman]

But, this study with the lighting guru Sanjay Joshi's name on it indicates how to measure a bulbs useful life. The corals which are the desirable focus for reef lighting will gain an acclimation to the aging output of the metal halide in their trial.
Good Luck on your quest.

CleveYank,

Which study? Do you have a link. I forgot all about Mr. Joshi. I heard a lecture by him at last year's MACNA and spoke with him for a couple of minutes after the lecture. Unfortunately, the lecture was about mistakes to avoid in setting up a tank, murphy's law kind of stuff, and not about lighting. My current tank was just finished before MACNA and I shared a 'fix' I had done that was just a small change/improvement in one he was recommending.

I will send him an email and ask for advise/help. Thanks for the idea and I appreciate your the tenor of your post.

Ron

 

[barjam]

http://www.americanaquariumproducts...._Lighting.html

This was an incredible article! It had tons of information and it was presented in a way that most people could understand it... well, most of it anyway. disc1, I really want to thank you for finding and sharing this article. Seriously, I learned so much about light that I didn't understand before. I'm even going to ask Carl Strohmeyer, the author of the article, to clarify and expand on the statement he made that I quoted below.

So in a HUGE article (only 1 page on the website, but it had a really long scroll bar) that covered a vast number of light related topics, this was all it had to say about old lights:

Changing bulbs:

With the exception of LED, most aquarium bulbs go through what is called a half life whereby they are at 50% output. This generally happens around 6 to 9 months in time with normal usage however with lower usage (say 8-10 hours per day) this can be stretched to 12 months.

It says 'most' bulbs... I think that implies 'not all' bulbs? So what are the exceptions? And it says nothing about a color shift with age. It says the bulb "output" is reduced to 50%. Output measured in what?

As I said above, thanks for the help with learning more about this and I'm composing a letter/email to send asking Carl Strohmeyer
for more information.

Ron

Phoenix 14k Bulbs are an exception to this. I suspect many others are too.

http://reefkeeping.com/issues/2007-04/ac/index.php

I run my Phoenix bulbs for 18-24 months. I have never had an algae issue that I could attribute to old bulbs.

 

[Ron Reefman]

OK guys, I just got a reply to the letter I sent to Sanja Joshi. Here is what he had to say about lights and algae:

Yes, all light bulbs including LEDs go through a decay in the output. Usually we end up changing bulbs at around 70% mark not 50%. With the warmer LEDs like 6500K Iwasaki, this could be almost 18-20 months, with 10K-14K this takes about a year to 15 months, and with the bluer ones you are looking at 6-10 months. With LEDs the claim is 70% of light output would be around 50,000 hours. !! Of course this is subject to ideal operating conditions.

I do not think there is a strong correlation of light from old bulbs and algae. I have been using MH for over 20 years now and would rarely ever be able to strongly attribute algae growth to age of lamps. If the nutrients are well managed this is never an issue. However, I have seen algae die off (esp cyano) after switching to new lamps. This could be due to change of spectrum causing it to go away.

I think the most important comment in his reply is, "œ I do not think there is a strong correlation of light from old bulbs and algae. I have been using MH for over 20 years now and would rarely ever be able to strongly attribute algae growth to age of lamps."

Take away from this what you will. I keep my nutrients well managed and I have great random current flow throughout the tank. I have very low expectations of algae outbreaks. And when it comes to my lighting, I'm about to completely change the color temps of the 5 bulb fixture over my 180g and even the single MH bulb over my 85g. I'll test PAR values and keep track of them over time. As output from the lights goes down, I'll lower the lights to keep the PAR values inline with the original levels.

When I get a reply from Carl Strohmeyer, I'll post his comments as well.

Ron

 

[disc1]

If the nutrients are well managed this is never an issue.

This is the most important sentence. IF nutrients are kept in check, then you can have whatever light spectrum you want and algae won't grow.

Old lights favor algae growth, but they can't create it out of nothing. There are a lot of factors in algae growth. If you have some algae in the tank, it will grow better under old lights. But old lights aren't by themselves the cause of the algae outbreak. Under the conditions of an outbreak, your old bulbs may be fighting against you in trying to get the algae under control. But if there isn't any NO3 / PO4 in your water, it's a different story.

Think about the guys that run natural sunlight. If you have a little bit of PO4 in the water algae goes crazy with that stuff. But if you keep your nutrients in check, then there's no problem with it.

 

[stanlalee]

fiction...I laugh everytime I hear that. if switching from 20k to 10k doesn't cause algae blooms in a well maintained aquarium a damn old bulb light shift with decreasing intensity all the while aint going to cause a bloom.

 

[Ron Reefman]

OK, one of Mr Carl Strohmeyer's associates has answered the questions I asked this way:

"Yes, most lights do loose there effectiveness, because most bulbs use gasses to produce light and the gas slowly gets used up. Most people that do get algae problems when there lights are older, usually have poor filtration as well.

Yes you can use a PAR meter to determine whether your light is less effective and the idea of lowering the light is a good idea, as long as it is not too close to the water (due to damage to the bulb or fixture)."

So again, the 'experts' kind of duck the issue. I asked both if the spectrum of the light changed as they get older and if that was part of the reason older lights are associated with algae growth, both failed to answer that question. It seems all they are willing to say is that the 'output' goes down. I take that to mean that it is putting out less light, not that the spectrum has changed.

I'm putting 6 new MH bulbs in my system and will test and monitor PAR output for as long as I use them... probably until the output falls below 50%. I can raise and lower my MH fixture to keep the PAR reading in the bottom of my tank stable.

Ron

 

[mahogue]

Ron, I found this cool inexpensive spectrograph they say you can build in 15 min.http://sci-toys.com/scitoys/scitoys/light/spectrograph/spectrograph.html This could help you in your experiment to see how the light spectrum shifts over time.

Thank you for contributing such a worthwhile experiment to the hobby!

 

[Ron Reefman]

mahogue, the spectrograph is very cool. Thanks for the link! I'm going to build one this weekend (and order the one part I can't get locally). Between that and the PAR meter, I should get reasonable data.

I'll be testing 2ea 150w 10K MH, 2ea 250w 14K MH and 2ea 250w 20K MH. This should be interesting. I'll post monthly results here in this thread.

 

[0 tds]

I'll post monthly results here in this thread.

Then I will follow along. Should be a fun ride. Thanks for taking the time to do this.

 

[disc1]

You are never going to get a satisfactory answer out of this.


The facts are thus:

Algae uses a slightly different photosystem than does the zooxanthellae in the coral. The light harvesting antennae in the algal photosystem utilizes a redder part of the spectrum. The zooxanthellae use the bluer end. This is an evolutionary effect from living underwater where red light gets filtered out.

Many algae are well adapted to living at depth, and can use the blue end of the spectrum just as well. In those cases no, they like the same light as the coral. Many algae can actually switch, depending on where they are and what light they are getting.

Without the nutrients being present, no amount of light can create algae. AND without light (ie total darkness) no amount of nutrients can create algae.

So the answer just isn't that simiple. There's not one rule that governs it. It will depend on the kind of lights, the species of algae, the other conditions in the tank. We cannot ever say that old lights have NEVER caused an algae outbreak. We know this to be true from empirical and observational evidence. It also cannot be said that old lights will ALWAYS cause an outbreak, by the same kinds of evidence.

All we can say, is that light is a possible contributor and each situation is different. I'm sorry man, but there's not going to be an end to this discussion for that very reason.

It's like arguing over whether or not going to college helps to get a better job. There's just not a simple answer to that. Sometimes it does, and sometimes it doesn't.

 

[indatank]

Tagging along also

 

[doctorgori]

You are never going to get a satisfactory answer out of this.


The facts are thus:

Algae uses a slightly different photosystem than does the zooxanthellae in the coral. The light harvesting antennae in the algal photosystem utilizes a redder part of the spectrum. The zooxanthellae use the bluer end. This is an evolutionary effect from living underwater where red light gets filtered out.

Many algae are well adapted to living at depth, and can use the blue end of the spectrum just as well. In those cases no, they like the same light as the coral. Many algae can actually switch, depending on where they are and what light they are getting.

Without the nutrients being present, no amount of light can create algae. AND without light (ie total darkness) no amount of nutrients can create algae.

So the answer just isn't that simiple. There's not one rule that governs it. It will depend on the kind of lights, the species of algae, the other conditions in the tank. We cannot ever say that old lights have NEVER caused an algae outbreak. We know this to be true from empirical and observational evidence. It also cannot be said that old lights will ALWAYS cause an outbreak, by the same kinds of evidence.

All we can say, is that light is a possible contributor and each situation is different. I'm sorry man, but there's not going to be an end to this discussion for that very reason.

It's like arguing over whether or not going to college helps to get a better job. There's just not a simple answer to that. Sometimes it does, and sometimes it doesn't.

Ya know when I see someone take time outta thier day to write down more than 4 word smart alec blast I'm appreciative (yes I know; pot calling kettle black but.....)
...anyway, also following along and I for one appreciate that well thought out explaination

 

[thebanker]

Tagging along with this thread. It's not a simple test, but I'm interested to hear if there is any evidence that supports the algae-from-old-lights argument.

 

[emkbass]

You are never going to get a satisfactory answer out of this.


The facts are thus:

Algae uses a slightly different photosystem than does the zooxanthellae in the coral. The light harvesting antennae in the algal photosystem utilizes a redder part of the spectrum. The zooxanthellae use the bluer end. This is an evolutionary effect from living underwater where red light gets filtered out.

Many algae are well adapted to living at depth, and can use the blue end of the spectrum just as well. In those cases no, they like the same light as the coral. Many algae can actually switch, depending on where they are and what light they are getting.

Without the nutrients being present, no amount of light can create algae. AND without light (ie total darkness) no amount of nutrients can create algae.

So the answer just isn't that simiple. There's not one rule that governs it. It will depend on the kind of lights, the species of algae, the other conditions in the tank. We cannot ever say that old lights have NEVER caused an algae outbreak. We know this to be true from empirical and observational evidence. It also cannot be said that old lights will ALWAYS cause an outbreak, by the same kinds of evidence.

All we can say, is that light is a possible contributor and each situation is different. I'm sorry man, but there's not going to be an end to this discussion for that very reason.

It's like arguing over whether or not going to college helps to get a better job. There's just not a simple answer to that. Sometimes it does, and sometimes it doesn't.

+1

This is correct!
Nutrients are present if you are growing algae. Bulb does not matter. If not you could change the bulb and the algae would die.


Gimme a nutrient laden tank and brand new bulbs and I'll grow you some algae

 

[disc1]

Gimme a nutrient laden tank and brand new bulbs and I'll grow you some algae

But also.....

Gimme a tank that is right on the verge of an outbreak, and let me put some year old T5's over it and 8 or 9 times out of 10 it will go right over the edge.

Same issue with sunlight. If you are maintaining right on the edge, then sunlight will absolutely push you over. Yet some people run tanks on sunlight alone without issues. But none of those people run nutrient rich systems.

 

[disc1]

I guess what I'm saying is that it is possible to get into a condition where the difference between a tank full of algae and something manageable comes down to light spectrum. In any of those cases, nutrient control would completely solve the issue. But that's where the people are that see an outbreak whenever their bulbs get old.

So my answer is still both yes and no. Depending on a multitude of other factors. But people seeing algae outbreaks when their bulbs need changing certainly happens in those cases.

 

[disc1]

To put it yet another way, depending on the lighting spectrum it might take more or less nutrients to grow the same algae.

 

[Ron Reefman]

disc1,

I'm glad to see that you are taking a more moderate position now. And I don't disagree with most of what you said in your last big post. Algae needs nutrients, no nutrients, no algae. The part I don't know, and have been unable to determine is, as bulbs get old is there a spectral shift that REALLY makes any difference to algae. I don't think there is.

I guess what I'm saying is that it is possible to get into a condition where the difference between a tank full of algae and something manageable comes down to light spectrum. In any of those cases, nutrient control would completely solve the issue. But that's where the people are that see an outbreak whenever their bulbs get old.
QUOTE]

Show me the articles by experts who agree with this point of view. Neither author I contacted said anything about the spectrum of the light changing being any issue at all. They say it's about the output not the spectrum. As lights get older you can lower them and 'in effect' raise the output in the tank. I've got Sonja Joshi and Carl Strohmeyer on my side.Quote me an expert (or two).

 

[thebanker]

I thought that old bulbs red-shifted slightly? (fluorescent or otherwise)

 

[disc1]

disc1,

I'm glad to see that you are taking a more moderate position now.

I've still got the same position. You want a single answer that applies to every situation and that does not exist.

It's one of those things that has just a grain of enough truth in it that we can't 100% call it a total myth.