"We get light," she says. "We're not so far down--our foundation is on the sea floor, but some parts are shallower than others, and the taller the buildings are, the more light they get. Where I live is over a trench, so it's darker, but even there you can tell the difference between day and night. But we take vitamins, and they had to make arrangements for the crops. They don't get quite enough natural light."