Will ambient light have a negative effect on the plants during the eight hour off cycle?
it depends on how intensive the ambient light during the night is. But, what are you currently growing?
Some species are more sensitive to “long day” than others, and mostly plants also need to have a time off period during 24h cycle.
I am growing Basil, Cilantro & Rosemary.
@herby, those plants you mentioned will be probably fine with some ambient light during the night. Cilantro is a short-lived plant anyway, Basil may develop a more pungent flavor and rosemary will be just fine. But yes, it all also depends on overall growing conditions as humidity, temperature, plant age etc
Thank you Mirjam. Your input is much appreciated and helpful.