Right so take this one:
https://www.google.com/search?q=seed...wd1EowriMmz9M:
Putting 4 1020 trays side by side per shelf rather than 2 lengthwise per shelf looks/sounds phenomenal for density - one shelving unit should get 72-96 plants from seed to plant out. But is a single two-bulb shop light still enough to cover the whole shelf? Or would you have to somehow mount two fixtures per shelf? Or just rotate the tomato plants so they receive similar lighting over time?