Bomb shelters as underground farms

It’s somewhat misleading in that the image of their produce is one of sprouts (or micro-greens as they term it), whereas mid-article there’s a picture of someone harvesting a full head of buttercrunch or some other lettuce. So, do they get enough light to churn out full plants or is it just tiny little micro-greens?
And while I think hydroponics is great stuff, there are issues with super-nutrient wastewater once it’s been used in a few grow cycles, as well as the problem of where those nutrients are harvested.
But hey, my idiot neighbor powers a small water fountain in front of his house that’s run dry most of the time, so who am I to complain?