Not to worry.Well I always heard to have a night/lights-out for planted tanks, but of course that was for rooted plants in soil tanks. I get that a plant is alive and performing it's functions even in the dark, so I believed (and shared) the advise to have a dark time. If this supposition is not correct, what is the scientific evidence? Is down time just about the water CO2 level? And fish comfort?
What then is the ideal photo period for a rooted-plant NPT with fish inhabitants? Keeping in mind algae and any other important factors.
The scientific evidence that I have recently found shows that several aquatic plants will grow much better with a longer photoperiod (that is, 22 hr and/or continuous light). This information is very useful for those setting up refugiums (water purification systems using aquatic plants) and those that grow aquatic plants to sell.
For ordinary situations and NPTS, I would follow what CS-Gardener recommends. My own tanks run with a 14 hr day and a 4 hr siesta. Works great!