pH stabalization using opposite light cycle. Is it necessary?

[Subsea]

As with many reefers, I have tried many things.  Over a 40 year period, I have thrown a truckload of gadgets away and went from Jaubert Plenumn, EcoSystem Mud Refugiums, DSB to shallow sandbeds.  Nothing has intrigyued me more than the light cycle for macro in the refugium.  I went from 24 hour lighs on using Caulerpa.  The idea was to prevent it from going sexual.  It seemed to work ok.  Then the opposite light cycle became the standard to stabalize pH during display tank lights out.  

 

The logic of steady state pH eludes me.  The ocean reefs do not have an opposite light cycle.  Why does there need to be one in our marine tanks.  None of my sumpless tanks have an opposite light cycle.  The pH fluctuations that I have seen are 8.1 - 7.8 with no tank problems. These small pH fluctuations have actually asisted with buffering and trace mineral addition by disolving aroggonite.

 

On my 75G display tank I have a Jaubert Plenumn with a mud/macro refugium.  It has been on an opposite light cycle for 10 years.  Last week I changed lighting schedules so that both lights on simultaneously for 14 hours.

 

We shall see if moderate pH fluctuations are good or bad for a mixed garden reef.