If you aren't sure if the filter is ready to be changed just remember this is what cleans the air you are breathing.

Never wash or reuse a disposable filter

Pleated filters remove more dirt from the air than fiberglass filters. But their density restricts the air flow more. This can create problems in some systems. Experiment with both and see which is best for you and your system.

Filters should be checked every 30 days on residential applications and every 15 days on commercial applications.