A Fluorescent Bulb is a gas-discharge type lamp that utilizes electricity to excite the gas within the bulb, mercury vapor. When mercury atoms are excited they produce an ultraviolet light which causes the phosphor within the bulb to fluoresce producing visible light. These lights come in several varieties ranging from the red to the blue side of the spectrum. While you can grow marijuana solely with these lights, you will never reach your cannabis’ plants full potential when using these. They have started manufacturing higher wattage fluorescent bulbs that are “full spectrum” lights, but you still won’t get the yield you will from HID bulbs. The “full spectrum” bulbs emit around 75 lumens per watt. They have a 10,000-15,000 hour life.
While fluorescent bulbs aren’t the best choice for the flowering stage of marijuana development, it is more than adequate for the vegetative stage or even just to grow your clones/seedlings. They will help you save some money on the electric bill rather than grow the entire time on HID bulbs which use more energy. Another advantage to these lights is that they operate a relatively low temperature which lowers the risk of you burning your plants.