As a rule of thumb, you should always clean the septic tank filter when doing your routine pumping. It is best to use a filter that has an alarm.
How Septic Systems Work, Conyers, GA
Sanitary Tee and Filter Statesville, NC
How to Improve Maintenance of a Septic Tank System - Aquatech Tanks
How to Clean a Septic Tank (with Pictures) - wikiHow
How to properly wash your septic tank filter
Septic Tank Filter Maintenance
Septic Systems: How They Work and How to Maintain Them - This Old
What Is a Septic Effluent Filter and Is It Necessary? – Fresh
Septic Tank Filter Need and How Often Should You Replace It?
Do You Need a Septic Tank Filter?
Septic Tank Pumping - Western Rooter & Plumbing