How long is your light cycle?

[Ike]

Photosynthesis is a more complicated process than simply something that occurs during the photoperiod non-stop. It is a two step process that first requires the capture of light energy to produce certain compounds. During the second stage, those compounds are used up to capture and reduce carbon dioxide which is converted into a carbohydrate. It is therefore possible for a coral to capture enough of the energy from photons during a certain period of time to produce enough of those compounds to fuel the growth of the symbiotic zooxanthelle (sp?) growing in the tissue of the coral itself. Corals themselves are not photosynthetic, but are rather animals dependent on exterior sources of energy...they are not plants. Since any reaction (oxidation or photosynthesis) is a limited reaction based on many factors, there is a definite law of diminishing returns involved (i.e. it's not a linear equation at all) and at some point (which can be debated all day, but actual evidence is largely anecdotal) you experience such a small return that you're wasting bulb life, and electricity.

I just love to see the stuff in my tank, that's why I run it 8 hours...not because I think it will give me better growth (or color) in my tank. From what I've observed of other people's tanks that run their lights for 5-6 hours, that's not the case at all.

Not disagreeing with anything you've said and I don't see how it refutes my statement, if that was your intention... But, to say "corals only need 4 hrs of full lighting to reach photosynthesis, anything after that is non beneficial" is quite false.

 

[cloakerpoked]

More of an aside than a refutation. I agree that 4 hours seems short to me...but it would depend on the tank, size of the corals etc. I guess if you're getting the results you want with a 4 hour lighting cycle, more power to you.