Why do we talk about PAR instead of PAR-hours?

[jnbrex]

When baking a cake, the instructions don't read, "Bake at 300 degrees". They read, "Bake at 300 degrees for 90 minutes".

2400 PAR for 1 hour is not equivalent to 300 PAR for 8 hours, so the intensity does matter. But within the acceptable intensity range, does coral biology work in such a way that a coral receiving 300 PAR for 8 hours would be similarly happy to a coral receiving 200 PAR for 12 hours? Both receive 2400 PAR-hours of light energy each day.

I'm excited to hear opinions about this topic!

 

[Solo McReefer]

 

[crazyfishmom]

I think more likely than not if you’re within the range of tolerance for the particular species you’re looking at then they’re close to equivalent however much like when you get a sunburn, if you’re pushing coral like most people do in their tanks then no they’re not equivalent and the higher PAR for the shorter time period may be better for some species while a longer photoperiod at lower intensities may be better for others. Some corals live in very shallow waters where they get sunlight from 6 am to 9 pm during certain times of the year. We can certainly do more to mimic exposure. It might be worth considering longer ramp up times and longer photoperiods etc. There’s still much we have to learn about caring for these amazing animals we love.

 

[rtparty]

If I understand correctly, you may want to look into DLI