EF 235

The all new EF-235 Septic Filter exemplifies BOWCO’s abilities to design, engineer and manufacture innovative products. With over 235 feet of 1/16″ filtration the EF-235 provides a simple, efficient solution for extending the life of the septic system while ensuring optimal performance.


• Fits inside any 4″ outlet tee for new or retrofit applications.
• Largest filter area of any 4″ cartridge filter.
• Unique 360o outflow design eliinates potential installation problems.
• Equipped with a 1/2″ threaded insert for the connection of a detachable extension handle to ease in the installation and removal of the filter.
• Seals above and below the septic outet, forcing all effluent through the filter cartridge medium.


• All materials used are non-corrosive, virgin polymers


• Residential and light commercial

Filter Area:

• 235 linear feet of 1/16″ filtration slots

Flow Rate:

• 1500 gallons per day


Operating Principle:

The Bowco EF-235 is designed to extend the life of your drain field by preventing suspended solids larger that 1/16″ from leaving the septic tank. By containing these solids in the tank, the life of the drain field is dramatically increased and costly repairs are avoided. Located in the outlet tee, the filter extends below the scum line yet stays above the sludge layer, withdrawing effluent from the clear water zone of the tank. The EF-235 provides a simple, efficient solution for extending the life of the septic system while ensuring optimal performance.


The Bowco EF-235 fits inside any 4″ SDR-35 or Schedule 40 outlet tee. Under most circumstances an outlet tee will already be installed in the septic tank. If not, install as shown in figure 1.

Step 1: Connect the optional extension handle to the top of the EF-235 (if desired).

Step 2: Slide the EF-235 into the outlet tee until the filter bottoms out in the tees upper hub.

Step 3: If used, the extension handle may be removed for use on other filters or left attached to the installed filter.


The filter must be cleaned on a periodic basis to maintain optimal performance. Under normal circumstances, the filter requires cleaning only when the septic tank is pumped; however, site-specific conditions may require more frequent cleaning.

Step 1: Attach optional extension handle (if desired)

Step 2: Remove the EF-235 from the outlet tee by pulling it straight up.

Step 3: Using water from a garden hose clean off the filter making sure the solids fall back into the tank but not into the outlet tee.

Step 4: Replace the filter following the above installation instructions.

Lifetime Warranty:

Every Bowco filter is guaranteed to be free from defects in material and workmanship for the lifetime of the homeowner/purchaser. Free replacement excludes all labor costs. Abuse or improper installation voids warranty.

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