Higher intensity short time or lower intensity for longer time

[brad65ford]

I know this isn't an easy questions to answer but i'm wondering in some of your guys experiences which is better? Right now i'm running 7 hours of full intensity on my setup wondering if its better to bring down the intensity and add a few hours of light.

 

[sahin]

I think it works out to be about the same. I have a dimmable T5+LED unit...hence I am running peak intensity for a shorter period and running a longer light cycle.

Essentially, the total daily light your corals would be getting is about the same.
Obviously if you reduce the PAR/intensity/peak period too much then your corals may turn brown since they wouldnt be getting enough light.

I feel that as long as there is a sufficient "PEAK" period, then the light levels either side of that can be run lower at a longer time period.

These articles should help you make an informed decision.

http://www.advancedaquarist.com/2009/5/aafeature

http://www.advancedaquarist.com/2013/9/aafeature

A lot more general info, but a good read
http://www.advancedaquarist.com/2013/12/lighting