Proper Lighting is the most important factor for high quality plant growth. When depending only on indoor lighting, making the correct choices will be very rewarding. The following will help you make the right decisions so you can get the most from your investment on Indoor / Outdoor gardening. It has long been known that the green parts of plants, when exposed to light under suitable conditions of temperature and water supply, use Carbon Dioxide from the atmosphere and release Oxygen to it. These gaseous exchanges are the opposite of those which occur in respiration and are the external manifestation of the process of Photosynthesis. The intensity, quality, and daily duration of illumination all have influence on the amount of Photosynthesis accomplished per day. The minimum light intensity at which a measurable rate of Photosynthesis occurs varies according to the species. Under natural conditions, maximum rates of Photosynthesis are attained in single leaves of many species at 25-35% of full sunlight intensity and in some shade species at even lower intensities.
For equal intensities, more photosynthesis appears to occur in the orange-short red and blue parts of the spectrum than in the green and yellow. In general, the longer the daily period of illumination, the more photosynthesis will be accomplished by a plant in the course of the day.
A: HID stands for High Intensity Discharge Lighting. They are more intense than any other Grow Lights available in the market today. They are good for growing vegetables, Flowers, and your favorite Herbs all year round.
Q: What are the differences between MH bulbs and HPS bulbs?
A: There are two types of HID Lights that are available. HPS which stands for High Pressure Sodium and MH which stands for Metal Halide bulbs. MH grow bulbs come in 175, 250, 400, 1000 and 1500 watt sizes, while the HPS grow bulbs comes in 150, 250, 400, 430, 600 and 1000 watt sizes. The difference between the MH and the HPS bulbs is that the MH provides a more intense blue spectrum for rapid growth, while the HPS provides a more intense red spectrum for seedling and cloning, as well as blooming and fruiting.
Q: How many Hours should I keep my Lights on in my garden?
A: This depends on what you are growing. For long day plants which includes Gloxina, Tomatoes etc. 16-18 hours of light and 6 hours of darkness are needed daily.
Q: How much Light do I need?
A: 20-40 watts per sq. ft. is a general guideline. The more efficient the Light source, the less watts per sq. ft. needed. For example using 1-1000 watt metal halide light, in a 50 sq. ft. area would give you 20 watts per sq. ft. and a total of 120,000 lumens. Compare this to 3-400 watts metal halide lamps in the same space which will give you 24 watts per sq. ft. and a total of 120,000 lumens. You will get more light from a single 1000 watt light while using less wattage per sq. ft. in addition to savings on timers, and outlets. As a rule, 20 watts per sq. ft. using 1000 watt metal halides is the absolute minimum required. Since a given amount of light can only do so much, the same production can be obtained in a smaller space with less plants because the light is concentrated, and the plants can work more efficiently. Using more light also helps additional CO2 up take.
As discussed previously, the more light on the plants, the faster they grow. NOTE: To increase the effectiveness of HID lamps, and to make it possible for plants to receive maximum light especially from the side, line the walls with Mylar plastic sheeting. This is fast, easy to install, and is the most economical way to take advantage of it's reflective properties.