Originally Posted by Steve001
Plants have the ability to handle cloudy days and days where sunlight fluctuates do to variable cloudiness. but nowhere on this planet do plants have 5 hours on followed by a break followed by 5 more hours. Always take your cues from your natural surroundings.
A tree can easily provide deep shade, regularly in the middle of the photoperiod, as the sun moves in the sky. So can other obstacles, both natural and unnatural.
Don't take nature too literally. The sun doesn't go on and off instantaneously with the flick of a switch each day, yet our aquatic plants in glass cages subjected to this and many other unnatural occurrences grow fine anyway.
I've tried breaks and found neither improvement nor harm. Some say it helps with algae problems. Others use it to better fit a limited photoperiod around their personal schedules, to increase viewing time.