Introducing the only scientifically-proven, non-toxic fungus gnat control: Gnat Nix! It's not just free of harmful pesticides and chemicals, it's made from 100% recycled glass. Plants love it. Gnats don't. University trials have proved Gnat Nix! used as a top dressing creates an effective physical barrier against fungus gnats. Unlike other top dresses that are limited to one phase of control, Gnat Nix! controls gnats at different stages of their lifecycle. It prevents adult emergence from hatching larvae and deters females from laying eggs in the growing media. As a result, the lifecycle of fungus gnats is interrupted and the population significantly reduced. All you need to do is apply approximately 1/2"- 3/4" thick layer of Gnat Nix! top dressing to fully cover the surface of the growing medium in your growing containers. Make sure the entire top surfaces of all your growing containers are fully covered at all times. Irrigate gently to avoid disturbing the protective physical barrier of Gnat Nix! That's it!.