Bought the stainless steel model with all timer settings.Don't have to do a thing but watch the lights and add the nutrient tablets and more water whenever the small lights flash. Planted the tomatoes kit, which I bought separately. (Came with herbs -- I'll grow those later.) Six weeks have passed now. The plants are getting full. Can't wait for actual cherry tomatoes in another 4 to 6 weeks. Instructions are easy to follow. With the grow lights that come with the kit, you can place the unit anywhere. No window needed.