I wouldnt suggest changing it unless you want to I've run caulerpa (both saw and grapevine in laymans terms) in both 24 hour and 16 on 8 off cycles without it going sexual. Most people associate it going sexual when lights off when it's really a genetic response to lack of nutrients. This is magnified by the lack of light for photosynthesis and thus the response occurrs. Having had it go sexual in a number of experiments I havent had any real bad problems with that either other than a green cloud to the water temporarily and lots of happy zooplankton.
Running the lights reverse in the
fuge to level
PH works due to the increased carbon dioxide usage of the
macroalgaes during photosynthesis. This can be helpful or moot point dependant on water volume and amount of macro. If your running a handful of macro in a 400 gallon system I wouldnt much worry as the co2 uptake of the macro is probably nowhere near enough to make the slightest difference. if your running a good amount of macro though this can be a signifigant help. All the same, it's always easier to go by the rule of thumb regardless of whether or not you think you have enough macro or not. rather than guess might as well go with it.
Long story short if your seriously scared of a sexual event run 24/7, otherwise most macro's prefer a 16 on 8 off cycle and low kelvin lighting (4100k on down) adjust to fit YOUR needs and on to the next project eh!
