Different light bulbs provide different parts of the spectrum, so some bulbs will work better than others for growing plants. Sunlight provides the full spectrum, and will probably be the most intense light source. Intensity of a light is determined by distance of the bulb from the plants as well as bulb wattage which can vary from 150 to 1000 watts. Each plant will require a different photo period, defined as the relationship between the length of the light period and dark period. Three of the most important are nitrogen, potassium and phosphorus.
Plants grow best with the right balance and concentration of nutrients.
Commercial fertilizers vary in the amounts of these essential nutrients that they provide. Also, different plant species have different nutritional requirements. Plants will grow best in a certain temperature and humidity range, which can vary with the species of plant. Plants grown in chambers often deplete available carbon dioxide, which can limit their growth. Ventilation and air circulation mixes the air and makes carbon dioxide available for plants.