When using a grow light for plants, you'll need to take a few components into consideration before deciding which type of light is best. Space, plant type and purpose all need to be explored before purchasing a grow light. Generally, fluorescent lights are the most versatile and frequently selected, but there are several other types available based on your needs and personal preferences.
Choose a location for your grow light and measure the available space with a tape measure. Grow lights are suspended above plants and usually require at least a few feet of open space. However, there are some types of lights that can be used in smaller spaces. If, for instance, vertical space is an issue, high-output fluorescent lights can be a good option. They put out twice the light as standard fluorescent bulbs while remaining cool enough to be suspended just a few inches over the plants.
Decide whether the light area will be temporary or permanent. Grow lights can be used before a planting season to start seedlings, or they can be used year-round to grow herbs and greens indoors. If the setup is temporary, that allows you to choose a system that may be a bit larger and more unsightly, but will offer quicker results (such as metal halide or high-pressure sodium lights). However, if the lights will be permanent, you may want to consider a small fluorescent system. These are easier to maintain than more expensive systems and take up less room.
Consider the type of plants being grown. Standard fluorescent grow lights let off the most comprehensive light spectrum, making them a great choice for most vegetables and plants. However, high-pressure sodium grow lights emit orange-red rays. These rays encourage reproduction and blooming in fruits and flowers, which in turn creates stronger plants.
Think about color rendering. Fluorescent grow lights produce seedlings that appear average in color. High-pressure sodium lights grow plants quickly, but the seedlings may appear pale and weak when they are under these lights. On the other hand, metal halide lights cause plants to appear lush and bright. Once the plants are no longer under the lights they will be fairly interchangeable, but if you are, for example, planning on displaying or selling the plants while they are under the light, you may want to choose a fluorescent or metal halide grow light.