The Bouncy Light Intensity Method

[Scrubber_steve]

Mike Paletta discusses at 12:28 using the method of alternating light intensity from 80% to 100% to 80% and so on during the illumination period. Europeans have great success using this method, Mike says.

Of course, I've read that continuously changing the settings on an LED is detrimental to coral growth.

So, is anyone here using the "bouncy" intensity method with success.

 

[Diesel]

Interesting.

Not to change subjects but it looks like it is working.

That said I’m from Europe and I’m not using it but I used to use the Diesel brew and with great success.

As you can see...

Oh and Michael have seen my tank in real life.

 

[mcarroll]

great success

I'm down for anything that someone claims "great success" with.

You might find this interesting...speaks to coral's fairly incredible ability to handle short-term intensity changes:
Flicker Light Effects on Photosynthesis of Symbiotic Algae in the Reef- Building Coral Acropora digitifera (Cnidaria: Anthozoa: Scleractinia).

You may also find @Dana Riddle's Feature Article: A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage very interesting.

The DLI is what counts on the video and is more or less what corals adapt to – not momentary changes.

 

[Scrubber_steve]

Perhaps @Mike Paletta could comment & provide some detail ?

 

[mcarroll]

Another thought on the vid....their lighting day could be extended even more if they'd just use a lower overall peak intensity level during the day.

This vid also goes into it:

 

[Ron Reefman]

Interesting.

That said I’m from Europe and I’m not using it but I used to use the Diesel brew and with great success.

As you can see...

Oh and Michael have seen my tank in real life.

Diesel, care to share the recipe for that 'brew'? The Browning and Seasoning Sauce and the Sweet and Sour Sause both have me interested. I'd love to here an explination of what they do for your brew. You could start a new thread or link me to one you may have done in the past?

 

[cracker]

I'm also curious ! I hope the Sweet& Sour is what he mixes his ingredients in. The browning seasoning?

 

[Dana Riddle]

As best as I can tell, the 'bouncy' method (aka 'hacksaw', 'zig-zag') is based 0n how zooxanthellae respond to light intensity. Zoox contain xanthophylls that act as protection against excessive light. As light intensity increases and exceeds the maximum amount of light required for max photosynthesis, the xanthophyll cycle kicks in and protects the coral/zoox from excessive light (but only up to a point.) I'm not sure where the idea that zoox need light for *six hours* and then photosynthesis slows or shuts down. I did some PAM fluorometry work with tidepool corals in Hawaii, and found they reached maximum photosynthesis as early as 9 or 10 am. In the afternoon, when light intensity decreases, this protective cycle decreases and rates of photosynthesis increase.
Again, I can only suppose that this concept is loosely based on the mechanics of photoprotection and effects of excessive light. If you are possibly over-lighting your tank (running LEDs at 100%) then the zig-zag lighting concept is probably a good thing. If you're under-lighting, it could have negative effects.
Mike mentions his (and Sanjay's) corals have vivid color. This is often the result of intense lighting, and likely another tool in the coral's arsenal against excessive light.
I'm not arguing that these guys don't have fabulous aquaria - they do! My point is that there is a misunderstanding among many as to why this concept could be beneficial. The fellow who taught me the ins-and-outs of a PAM fluorometer was Dr. Miguel Oliazola, who, along with Falkowski, described the xanthophyll cycle. I am forever indebted to him for taking time out of his busy schedule and answering all my stupid questions.

 

[Scrubber_steve]

As best as I can tell, the 'bouncy' method (aka 'hacksaw', 'zig-zag') is based 0n how zooxanthellae respond to light intensity. Zoox contain xanthophylls that act as protection against excessive light. As light intensity increases and exceeds the maximum amount of light required for max photosynthesis, the xanthophyll cycle kicks in and protects the coral/zoox from excessive light (but only up to a point.) I'm not sure where the idea that zoox need light for *six hours* and then photosynthesis slows or shuts down. I did some PAM fluorometry work with tidepool corals in Hawaii, and found they reached maximum photosynthesis as early as 9 or 10 am. In the afternoon, when light intensity decreases, this protective cycle decreases and rates of photosynthesis increase.
Again, I can only suppose that this concept is loosely based on the mechanics of photoprotection and effects of excessive light. If you are possibly over-lighting your tank (running LEDs at 100%) then the zig-zag lighting concept is probably a good thing. If you're under-lighting, it could have negative effects.
Mike mentions his (and Sanjay's) corals have vivid color. This is often the result of intense lighting, and likely another tool in the coral's arsenal against excessive light.
I'm not arguing that these guys don't have fabulous aquaria - they do! My point is that there is a misunderstanding among many as to why this concept could be beneficial. The fellow who taught me the ins-and-outs of a PAM fluorometer was Dr. Miguel Oliazola, who, along with Falkowski, described the xanthophyll cycle. I am forever indebted to him for taking time out of his busy schedule and answering all my stupid questions.

Thanks Dana, very informative.

 

[AlexStinson]

Very interesting! would the constant up/down have any effect on LED's lifecycle?

 

[Dana Riddle]

Very interesting! would the constant up/down have any effect on LED's lifecycle?

I'm going to *guess* that less voltage to the LED would decrease its operating temperature and perhaps extend its life. I'll leave a definitive answer up to an engineer.

 

[mcarroll]

Dr. Miguel Oliazola, who, along with Falkowski

Is this a correct list of articles for Dr Oliazola? (typo?)
https://scholar.google.com/scholar?q="M+Olaizola"

(As far as I can tell, ignore the profile link at the top of the results. I'm just looking at the articles they found)

This sees to be correct for Dr Falkowski, but can you confirm?
https://scholar.google.com/citations?user=4lHobcAAAAAJ&hl=en&oi=sra

 

[Dana Riddle]

Yes, that are some of Miguel's papers. He's a super nice guy - had him over to the house when I was in Hawaii. I've never met Falkowski, but mutual friends Miguel and Charles Mazel have co-authored peer-reviewed research papers.

 

[Dana Riddle]

Yes, that are some of Miguel's papers. He's a super nice guy - had him over to the house when I was in Hawaii. I've never met Falkowski, but mutual friends Miguel and Charles Mazel have co-authored peer-reviewed research papers.

*those* are....

 

[Michael Benz]

Alex, Regarding your question on cycling LED high and lower. Should have no effect on LED life. Cycling on/off can have an effect due to the fact that the components. Solder joints, etc are going through hot/cold cycles, the solder especially can be vulnerable due to expansion and contraction during this process. Manufactured correct however it should be no problem.

 

[Da8]

Interesting.

Not to change subjects but it looks like it is working.

That said I’m from Europe and I’m not using it but I used to use the Diesel brew and with great success.

As you can see...

Oh and Michael have seen my tank in real life.

Cmon what happened with this brew ?


Would love to know more about the Chinese sauce and the zig zag lighting scheme!

 

[Dana Riddle]

Very interesting! would the constant up/down have any effect on LED's lifecycle?

Heat is the enemy of LEDs, so the 'bouncy method' *might* actually extend the life of LEDs.

 

[User1]

Heat is the enemy of LEDs, so the 'bouncy method' *might* actually extend the life of LEDs.

Very true. This is one of the reasons why I was personally interested in the new Philips lights with their passive cooling unit with its massive heat sink. On one hand it looks great because it has the better cable management and no power brick. On the other one has to wonder how it handles thermals.

On the bouncy thing I'm not sure how the corals would react. I mean my simple mind says that Mother Nature isn't flipping a switch on or off to adjust the sun. However, there are clouds and other weather activities that muck up the sun power which is interesting.

I can't speak for GHL or Apex (and I have a Apex) but the reef angle controller has an amazing custom library to simulate clouds and other weather patterns. It isn't on/off based on a time of day but rather part of the main control loop so it is always checked and completely random. I always loved that feature to include geo location for flow if you want.