Does a septic tank need a filter? Always 25% In some cases 25% Not sure 50% Get Free Quotes Today! Question: Does a septic tank need a filter? Top Answer (50% of 4 votes): Not sure. Answer: In some cases Explanation: Depending on the type of system you require its good to have a filter. DeLaTorre Septic Answer: Always Explanation: Solids need to be filtered out prior to exiting to leach field. Bayshore Construction Get Free Quotes Today! Find Local Pros Free Septic System Installation Cost Estimates Related Questions How Much Does It Cost to Put in a Septic Tank? What is an Engineered Septic System? What is a Septic Baffle? What is a Septic Alarm? What is a septic Lid?