Beyond PAR - DLI in the Reef Aquarium

[shiftline]

We measure light we used to grow coral with PAR (Photosynthetically active radiation) But have you ever considered Par vs the duration of your lighting schedule?

For example 200 Par for 5 hours in one tank is completely different from 200 par over 10h in another tank. Thats over double the photons hitting the coral. You really do need to take PAR as well as duration into consideration to get a picture of how much light energy is hitting your corals.

Today we dig in to DLI (Daily light integral) with Patrick from Reef Wholesale who was a key part of the EcoTech Marine coral labs study

 

[JaimeAdams]

Thanks for sharing.

 

[reefwiser]

HA HA HA HA. very funny that is like saying that plants will grow better with lights on 24 hours a day. There must be a rest period for the coral to process the sugars that amino acids that the zooxanthellae produce. I have seen this type of thinking before down thru the years. You start stressing the coral out when you do this.

 

[shiftline]

Not at all. Corals need and can accept a certain amount of photons of light energy in a given day. The comparisons is of testing less light energy for a longer duration vs a high amount of light energy for a shorter duration. And yes there is a point of max saturation where corals will stop absorbing and block the light (dana riddle did a very good talk on that topic) ... Per your plant reference DLI is actually very widely used in horticulture but rarely talked about with respect to corals.

 

[oreo54]

HA HA HA HA. very funny that is like saying that plants will grow better with lights on 24 hours a day.

some do... some don't... Dark reactions occur in both light and dark..