GROW!T Perlite is a versatile and inert soil amendment and soilless medium. Use it to aerate soil in container gardening, for germination and propagation of seedlings, for propagation of cuttings, and as a hydroponic medium. Hydrofarm searched globally and went to great lengths to find a source of top-quality perlite, and succeeded-and what we found is offered in the GROW!T line of perlite products. Multiple grades available: #2 Perlite (1/16" - 5/8" granules), #3 Perlite (1/8" - 5/8" granules), #4 Perlite (1/3" - 3/4" granules), and #8 Perlite (3/4"-1 1/3" granules).