PAR on shallow reef in the wild?

[PlasmaBoy]

Does anyone know what the PAR would be for shallow lagoon style reef I the wild, so 1-5m depths average clear water ? I’m guess 1200 ish peak ? Most of our SPS are collected at these depths ? As our tanks have crystal clear water 600 is the sweet spot ?

 

[Epic Aquaculture]

I'm sure @Dana Riddle can answer that for you.

 

[naoki]

When you are comparing the natural to artificial light, Daily Light Integral (DLI) of PAR is probably more appropriate than Photosynthetic Photon Flux Density (PPFD, which is what you get from the Quantum PAR meter) of PAR. Here is some values for DLI from Australian reef (Table 1):

https://www.sciencedirect.com/science/article/pii/S0141113619300601
At 2m, DLI is about 20 mol/m^2/day in the winter and 30 mol/m^2/day in the summer (more variable in the summer, though). With constant artificial light, PPFD of 463 micromol/m^2/s for 12 hours per day will give 20 mol/m^2/day of DLI.

But what they experience in the nature may not be the best under cultivation.

 

[Dana Riddle]

I measured 1,800 micromol/m2/sec at 1m depth on a reef flat in Hawaii at about noon on a clear July day. I assume a lagoon would have less since the water is impounded (sort of.)
Here's an article I wrote 6 years ago on DLI.
https://www.advancedaquarist.com/2013/9/aafeature

 

[Dana Riddle]

 

[Dana Riddle]

 

[PlasmaBoy]

Thank you for the info, now I have to guess what corals are collected in the 5-15 feet range. Would u agree most are in the 5 to 15 feet range? I’m actually running my tank with 6500k during the day which is what most shallow water corals would see. The kelvin range in the first 15 feet would be hardly effected ? Basically trying to emulate the light kelvin, par and spectrum of where our corals are collected. I’m using Plasma LEP for my main grow lighting and leds for night viewing. Hopefully this doesn’t upset them, with the spectrum change.

 

[PlasmaBoy]

Mmm gives some idea to the depths per species

https://www.daf.qld.gov.au/__data/assets/pdf_file/0020/71039/EcolRiskAsses-Coral-Vulnerability.pdf

 

[Big E]

One thing to keep in mind is that the earth is revolving around the sun so each part of a coral, especially when they get big, isn't getting bombarded with that high par all day.

Since our lights are static you can go by at least half that par or less is needed for corals to thrive in our systems.

 

[PlasmaBoy]

Very true, I have thought about a light rail, but the unit is 20kg. I think this is where T5 lighting works well, a nice dousing from all directions.

 

[Dana Riddle]

Mmm gives some idea to the depths per species

https://www.daf.qld.gov.au/__data/assets/pdf_file/0020/71039/EcolRiskAsses-Coral-Vulnerability.pdf

Thanks for sharing. We're hosting the family for Thanksgiving, so I'll review this as soon as I can.