Media filters are used to protect water quality in streams, rivers, and lakes. They can be effective at removing pollutants in stormwater such as suspended solids and phosphorus. Sand is the most common filter material. In other filters, sometimes called “organic filters,” wood chips or leaf mold may be used.

Activated carbon filters are most effective in removing organic contaminants from water.

Filter media will work best when kept clean and changed at regular intervals. Depending on various factors, a monthly rinse of filter media coinciding with that week’s water change might be the ideal basis for a regular maintenance regime.