High intensity vs Long Duration?

[thresher]

So here's one rattlin' around in my head. Would sps prefer (better growth) a shorter burst of high intensity par vs a long duration of even medium par?

 

[bakbay]

Some ladies on this forum might get “excited” from this title alone! lol

If you’re referring to SPS, they prefer slow ramp up / down with peak period of 4-6hrs. Curios to hear what other experts’ lighting schedule looks like.

 

[Tangerine Speedo]

Reminds me of a joke... Two Bulls, a father and a son were standing on a hill looking down in a field full of cows.
Can you name the movie....?

 

[Tangerine Speedo]

"The intensity of light is in direct correlation with the intensity of water movement..."
Jake Adams...

 

[bakbay]

Reminds me of a joke... Two Bulls, a father and a son were standing on a hill looking down in a field full of cows.
Can you name the movie....?

City Slickers. Billy Crystal?

Maturity is a beautiful thing

edit: is greed good or funny?

 

[Tangerine Speedo]

City Slickers. Billy Crystal?

Maturity is a beautiful thing

edit: is greed good or funny?

No.... Wrong...

 

[bakbay]

Hmmm pretty sure I know the parables tho. So you’re going “gangsta” on us?

 

[thresher]

WTH my thread has been hijacked!!. I can't get any straight answers from you knuckleheads

 

[Tangerine Speedo]

WTH my thread has been hijacked!!. I can't get any straight answers from you knuckleheads

See post #4
For me I pretty much do 12hrs. 6am to 6pm. I do this so I can check the tanks for any late night shenanigan’s before I go to work and some lovely late evening blues when I come home for work. I do a ramp up and down peaking around lunchtime.

 

[Jimbo327]

I schedule lighting around my viewing enjoyment & availability. Not coral growth. If the coral grows slow, so be it. Mine is lit from 9am to 9pm. And I like the blues after 6pm, so it’s nice to put on orange glasses to view.

 

[joseserrano]

You could do a short 100% 4 hours, and just do light blues for the reminder if you wanted, or so moderate light for 12-16 hours if you wanted. There are articles on the corals use the light over time

 

[drexel]

It's actually based on DLI, so you have to calculate intensity and time to see if you have enough. Dana Riddle wrote an article about this somewhere. I'll see if I can dig it up.
Also, spectrum is another factor.

 

[drexel]

https://reefs.com/magazine/imitatin...sage-in-a-reef-aquarium-do-we-really-want-to/


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[drexel]

https://horticulturelightinggroup.com/blogs/calculators/converting-ppfd-to-dli


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[thresher]

https://horticulturelightinggroup.com/blogs/calculators/converting-ppfd-to-dli


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This is what the doctor ordered! Thank you. Oh, keep the comedic relief coming. Glad I spelled that word correctly.

 

[mescobar]

Thanks for sharing the article, lot of cool insights from giving it a read. A couple of cool tidbits that stood out to me:

• Yellowing water due to DOCs changes the spectrum, the yellowness absorbs ultraviolet, violet, and blue light. Might have implications for reefers who don't do water changes. I won't list names, you know who you are
• At 10ft depth only ~2% of the total sunlight light is in the 600-700nm range. Do we need even more blue LEDs lol? I'm assuming this research has been used to design LED fixtures for quite some time now.

I wish the finding of the article were a bit more conclusive. It suggests might be overdosing light to corals with 8-12hr light cycles. Since sun's intensity at 10ft is highest around noon around 600-800 PAR; and the PAR intensity looks to follow a parabolic shape. Since a lot people (including myself) tends to run ramp schedules targeting 300-400 PAR for a longer period and we still give the corals less total light than the sun. The sunlight at 10ft gives ~25 mol·m²·d amount of DLI, while reef tank is between 12-15 mol·m²·d. The article suggests that our homes give constant light to the tank, 365 days out of the year. Since we don't have clouds/storms and changing sun intensity due to seasons like in nature, we may be giving our corals too much total light over the course of the year.

The somewhat inconclusive argument of the article is that corals are extremely adaptable, and we're still able to grow corals in captivity. So it worth trying to mimic nature if we still can grow coral with our current LEDs? I suppose growth might be different than thriving. If we mimicked the sun more accurately maybe we'd have more growth and maybe even spawning.

 

[thresher]

Nice summary mesco! Your cliff notes version helps mentally defunct peeps like me.

 

[mescobar]

Ah, gave the article another read, and I must have misread some of the arguments. The light intensity and duration doesn't matter so much as the total amount of light that the corals get in a given day. They recommend a 10-15 DLI (higher bound for SPS). This is was AB+ is suppose to provide over a 12 hr light cycle.

In Hawaii @ 10ft the amount of sun the corals get:

• Summer DLI (sunny) – 33.7 DLI
• Summer DLI (cloudy) – 22.9 DLI

How do we calculate DLI?

• DLI = (PAR * 60 (seconds) * 60 (minutes) * Hours) / 1,000,000

For an average reef tank of 250 PAR for 12 hrs (simplification) would get a DLI of 10.8

If you wanted to take into account the ramp up and down you'd add the each together:

• Ramp Up: 100 PAR x 2 hrs x 0.0036 = 0.72
• Peak: 300 PAR x 6 hrs x 0.0036 = 6.48
• Ramp Down: 100 PAR x 2 hrs x 0.0036 = 0.72
• Total DLI = 7.92

 

[rishma]

I fell down this rabbit hole last year. I found several papers, one by Sanjay and others by non-hobby types. The conclusion I took away was a parabolic profile with peak mid-day was good for shallow water SPS and a longer plateau was good for deeper water LPS. In both cases it would mimic what they see in the natural reef and aligned with different photo adaptations. There were some caveats for both, mostly around too much light. I don’t recall all the science but that is what stuck in my brain.