The Hayward Perflex W3EC40AC is a 20 sq ft extended-cycle D.E. pool filter for above-ground pools. Patented Flex-Tube design cleans without backwashing. 4 lbs D.E. capacity, 40 GPM max flow, 2-micron filtration. Clamp assembly included. 1 year warranty.
Hayward Perflex W3EC40AC 20 Sq Ft Above-Ground D.E. Filter: Extended-Cycle Filtration Without Backwashing
The Perflex W3EC40AC is the entry-level above-ground PerFlex model, providing 2-micron D.E. filtration for above-ground pools without a backwash valve, drain line, or grid teardown. The patented Flex-Tube design cleans through a bump handle instead of backwashing — stop the pump, stroke the handle eight times, and restart. The existing 4 lb D.E. charge redistributes and recoats the Flex-Tubes, restoring filtration without discharging media or wasting treated pool water.
The clamp assembly allows quick access to the filter interior without tools. If you also need a pump, the W3EC40C92S bundles this same filter with a 1 HP PowerFlo Matrix pump. For more filter area at the same above-ground scale, the W3EC50AC (25 sq ft, 50 GPM) is the step up.
Hayward W3EC40AC Perflex D.E. Filter Key Features
- Patented Flex-Tube design – Bump-to-clean mechanism reuses D.E. powder rather than flushing it, extending filter cycles and eliminating the need for a backwash valve or drain line.
- 2-micron filtration – Removes particles significantly finer than sand or cartridge filters, capturing dust, pollen, and algae spores on the first pass.
- Clamp assembly – Tool-free access to the filter interior for inspection, D.E. recharge, and Flex-Tube servicing.
- Self-venting design – Automatically expels air from the system through the filtered water returning to the pool.
- Integral check valve – Prevents system backflow whenever the pump is off, protecting D.E. coating on the Flex-Tubes.
- Combination pressure gauge and service port – Easy to read, easy to remove when the filter needs servicing.
- Heavy-duty glass-filled PPL tank – Corrosion-free construction for outdoor above-ground pool installations.
Hayward W3EC40AC Perflex D.E. Filter Specifications
SKU / ModelW3EC40AC Filter TypeExtended-cycle D.E. (Flex-Tube) Filter Area20 sq ft D.E. Capacity4 lbs pool-grade D.E. powder Max Flow Rate40 GPM Filtration Range2 microns Backwash Valve RequiredNo Cleaning MethodBump handle; no backwashing Port Size1.5″ NPT inlet and outlet Internal ElementPatented Flex-Tube elements Check ValveIntegral; prevents backflow when pump is off Air ReliefSelf-venting; automatically expels air Tank MaterialHeavy-duty glass-filled PPL; corrosion-free ApplicationAbove-ground pools Warranty1 year
Hayward Perflex D.E. Filter Lineup
Above-Ground Perflex D.E. Filters
| Product | Filter Area | D.E. Charge | Flow Rate | Pump |
|---|---|---|---|---|
| Hayward Perflex D.E. Filter with Clamp 4 lb (this model) | 20 sq ft | 4 lbs | 40 GPM | Filter only |
| Hayward Perflex D.E. Filter System 4 lb 1 HP Pump | 20 sq ft | 4 lbs | 40 GPM | 1 HP PowerFlo Matrix |
| Hayward Perflex D.E. Filter with Clamp 5 lb | 25 sq ft | 5 lbs | 50 GPM | Filter only |
| Hayward Perflex D.E. Filter System 5 lb 1.5 HP Pump | 25 sq ft | 5 lbs | 50 GPM | 1.5 HP PowerFlo Matrix |
In-Ground Perflex D.E. Filters
| Product | Filter Area | D.E. Charge | Flow Rate |
|---|---|---|---|
| Hayward PerFlex 27 Sq Ft D.E. Filter | 27 sq ft | 6 lbs | 67 GPM |
| Hayward PerFlex 40 Sq Ft D.E. Filter | 40 sq ft | 7 lbs | 80 GPM |
Hayward W3EC40AC Perflex D.E. Filter Frequently Asked Questions
No. 4 lbs of pool-grade diatomaceous earth must be purchased separately. Add D.E. through the skimmer with the pump running after initial setup. Do not use food-grade, pest-control, or industrial D.E. Perlite is a compatible silica-free alternative.
When pressure rises 10 to 12 PSI above the clean baseline, stop the pump, push the bump handle down slowly then up briskly, repeat 8 times, and restart. The Flex-Tubes compress and release, redistributing the D.E. cake so it recoats the tube surfaces. No water is discharged and no fresh D.E. is needed in most cases.
Filter only. If you need a matched pump, the W3EC40C92S pairs this same filter with a 1 HP PowerFlo Matrix pump.
D.E. filters to 2 microns — significantly finer than sand (20-40 microns) or most cartridge filters (10-15 microns). The tradeoff is that D.E. requires periodic recharging and the Flex-Tubes need occasional inspection and eventual replacement. The PerFlex bump design substantially reduces the frequency of full D.E. recharges compared to a conventional D.E. filter.
Hayward Perflex W3EC40AC D.E. Filter Manual and Warranty Info
- Hayward Perflex W3EC40AC – Owner’s Manual (PDF)
- Hayward Perflex W3EC40AC – Parts Diagram and Replacement Part Numbers (PDF)
