The Perlite #3 maximizes nutrient uptake, drainage, and aeration and helps prevent water rot at the root level thanks to its large coarse particles. Can be used either as a stand-alone medium in drip systems.The Perlite #3 maximizes nutrient uptake, drainage, and aeration and helps prevent water rot at the root level thanks to its large coarse particles. Can be used either as a stand-alone medium in drip systems or as a mix-in element with other growth mediums.