View Full Version : Intensity vs. Duration

03/03/2008, 07:53 AM
As far as reef tanks go, does 100 watts for 10 hours equal the same amount of lighting as 1000 watts for 1 hour?

Obviously the light penetration is less but does the length of the photoperiod make up for that?

This is just a hypothetical question or course.

03/14/2008, 10:33 AM
I'm not too sure but, I would think that the coral needs the period in order for it to grow properly. IMO

03/14/2008, 11:29 AM
Yeah, but I'm not talking about super short photoperiods. Obviously, if you exposed the coral to a day's worth of sunlight in 1 hour, you'd fry them.

I'm talking more about a 6-8 hour photo period compared to a 12 hour photo period.

03/14/2008, 11:30 AM
<a href=showthread.php?s=&postid=11996731#post11996731 target=_blank>Originally posted</a> by Paradiddle7
As far as reef tanks go, does 100 watts for 10 hours equal the same amount of lighting as 1000 watts for 1 hour?

I think from a coral perspective the answer is no. first off they are somewhat cyclic and need rest and non light periods in a 24 hour day. They photosynthesize only part of the day, rest part and take in nutrients, and process sugars that they made during the photosynthesis process.

I would think that all corals are not the same so there is probably not a single perfect answer that fits all. I use to be in a school of thought that a long intense but not too intense photoperiod was good. Now I’m going toward a long lower intensity photoperiod supplemented by a short high intensity photoperiod. I also understand some corals may actually shut down the photosynthesis process during high intensity times of the day so in some cases this may be counter productive. I was leaning toward this approach strictly based on what happens naturally. But, after seeing MakoJ’s set up and what he’s getting out of the corals on a short but intense photoperiod I’m thinking shorter but intense is generally better then longer less intense. Makoj is running 3 400’s in some excellent reflectors for about 5 hours if I recall correctly

By the way - great question - I would like to see what some of the experts have to say.

03/14/2008, 12:40 PM
I just posed this same question in the advanced topics about 5 days ago. I've got some good replies. Look it up