Oh and I forgot to ask, should this be 16 hours of continuous light, or
does it not matter? Let's say for example that I get 8 hours of sun
where I live, and I want to boost this to 16, should I give them those 8
extra hours in the middle of the night, or time it so they get the 16
hours together, and then 8 hours of darkness as a chunk? Do plants have
some thing analogous to a circadian rhythm?

Cheers,
Xi