Yes, it is necessary to use reflectors and diffusers when growing cannabis indoors with grow lights. Reflectors help to spread the light evenly across a space, creating an even canopy of illumination which promotes healthy plant growth. Diffusers are also beneficial in that they help reduce heat generated from the bulbs, as well as create a softer quality of light which helps plants stay strong and healthy. Both reflectors and diffusers can be used together for optimal performance. By using both reflectors and diffusers, growers can maximize their grow light’s potential while still keeping temperatures at safe levels for the plants.