VEVOR Plant Shelf with Grow Light, 6-Tier Double-Row Plant Stand, 71in Tall Indoor Plants Display Rack with Wheels & Timer, 200W Full Spectrum Grow Lights, Metal Flower Pot Holder for Seed Starting

Hi. I wanted to know if the lights that come with this shelf are sold in a set or individually with the connectors. I wanted to add more of the same to my shelf. It seems like one row per shelf isnt strong enough coverage for a tray of seedlings.