Blue Mountain Mesh™ improves water quality because it helps ensure healthy gutters. It prevents leaves and debris from blocking gutters. It is designed to shed leaves and allows sunlight and wind into the roof gutter system helping them to dry out quickly. The mesh used in Blue Mountain Mesh™ in not too fine - fine mesh lints up and gets blocked and creates a shadehouse for spiders. Blue Mountain Mesh™ allows visual inpection of the system at all times and can be hosed or blown out if required.