Qualm entered English in the 16th century, with meanings like doubt and uneasiness.. Usually a qualm comes from doubt about an action and a feeling that you are doing, or are about to do, something wrong. It isnt a bad feeling about another person's behavior but about your own.
The newest type of grow lights use LED technology. One major advantage to the LED lights is the small size. LED lights are only a few inches in diameter and are easy to mount. In some greenhouses, LED lights may be the only practical light option.
Incandescent Lights. Incandescent lights are good for lighting up a room or growing low-light houseplants, such as vines, ferns or dracaenas. They have limited utility for growing plants with higher light requirements. These lights put out only about 10 percent of their energy as light while 90 percent is heat.