Agent dispersing method

A gutter guard for filtering water that enters a rain gutter on a building, the gutter guard comprising:

• a barrier member configured to be positioned above a lowest portion of the rain gutter and having a plurality of openings through which the water can penetrate the barrier member and enter the rain gutter, the barrier member having
• first members that extend along a first direction;
• second members that extend along a second direction that is non-parallel to the first direction;
• and
• third members that extend along the second direction,
• wherein the first members are made of a first material,
• the second members are made of the first material,
• the third members are made of a second material,
• the first material and the second material are different materials,
• the second material is an ion-dispersing material,
• the barrier member is a single-layer mesh, and
• the single-layer mesh comprises the first members, the second members, and the third members.