How to Clean Your Septic Tank Filter

1. Wear gloves and protective gear. You’ll be handling wastewater.

2. Remove 2nd lid on the septic tank to expose the filter. Remove the filter. Look for a colored handle (red, blue, gray, or yellow) and pull it out gently.

3. Rinse it with a hose. Spray thoroughly until the filter slots are clean and you can see through them.

4. Reinstall correctly. When placing it back, follow any arrows or labels like “outlet this way.” If it's an arrow, make sure the arrow points in the direction of flow. Listen for the click. Not putting it in properly will cause a blockage in the tank.

Tip: Rinse over the open tank or into a bucket—don’t dump wastewater on your lawn.

How to Find the Filter

Filters are in the outlet baffle of the tank (where water exits to the drain field). Most systems installed since the early 2000s have them. Look for access lids at or near ground level.

Not sure which pipe is which? Have someone flush a toilet while you watch the tank:

• Water entering = inlet (no filter here)

• Opposite side = outlet (the filter is inside)

If you can’t see through the pipe and spot a handle or cage—that’s your filter.

How Often Should It Be Clean? At least once a year.

Even if your tank is pumped regularly, checking and cleaning the filter at least twice a year is smart choice.

A clogged filter can slow drains, cause backups, and damage your drain field. Left unchecked, solids may escape into the system, leading to expensive repairs. The fix? A quick rinse and reinstall. Simple upkeep now can prevent major problems later.