When it comes to installing the lights, you will have two options. The first one is using hanging panels to place the lights on the ceiling or some kind of construction. The alternative is using a lamp that allows clamping the unit to the surface, such as a table. In both cases, the lights will go above the vegetables. The ideal height will depend on the light strength. Compact lighting solutions can be placed up to ten inches above the plants. However, strong lights that emit 1,000W or more should go 20-40 inches or higher above the vegetables. As for the hours of operation, seedlings need from 14-18 hours of light per day. You can achieve the desired results with approximately 12 hours per day, especially when combined with at least some natural lighting.