Hayward Perflex D.E. Filter

The Perflex is Hayward's bump D.E. filter. Inside there are no flat grids. There's a nest of flexible fabric tubes, which the manuals call flex-tubes and Hayward's knowledge base calls fingers, and the D.E. coats those. A bump handle on top shakes the powder off the tubes and lets it coat them again, which Hayward calls regenerating. So one charge of D.E. lasts through many cycles, and the filter never backwashes. There's no backwash valve at all. When the powder is spent, you drain it out.

Hayward sells four sizes: the EC40AC, EC50AC, EC65A and EC75A. Add W3 to the front and it's the same filter in Hayward's Open Line; what changes is the warranty.

Four sizes, two kinds of tank

Hayward's figures:

• EC40AC: 20 sq. ft., 40 GPM, 4 lb of D.E.
• EC50AC: 25 sq. ft., 50 GPM, 5 lb
• EC65A: 27 sq. ft., 54 GPM, 6 lb
• EC75A: 40 sq. ft., 80 GPM, 7 lb

The EC40AC and EC50AC are the smaller tanks, closed with a clamp around the top. Hayward lists them for above-ground and in-ground pools, and sells them alone or as a system, with a pump beside the filter on one molded base.

The EC65A and EC75A share one tank. The manual gives the same head, body and bolts for both, and Hayward lists both at 31 inches tall. The difference is inside: 120 tubes on each, but the EC75A's are 16¼ inches long against the EC65A's 13⅜. Hayward lists them for in-ground pools.

Two flow ratings on the bigger two

The manuals give the EC65A 3,240 gallons an hour and the EC75A 4,800, which is 54 and 80 GPM, and the Expert Line product pages say the same. Hayward's Open Line pages add a residential figure: 67 GPM for the W3EC65A and 100 for the W3EC75A.

The two are different bases. 54 and 80 are 2 GPM per square foot of filter; 67 and 100 are about 2.5. Hayward's ProGrid carries the same pair of ratings. The EC40AC and EC50AC are 40 and 50 GPM on every page. Size by the lower figure. The filter sizing guide covers matching filter to pump.

Where it can sit

The manuals disagree by size, so check yours.

• EC40 and EC50 systems: the manuals say the system must sit below the pool's water line.
• EC65A and EC75A: below the water line, or up to 2 feet above it with a self-priming pump. Hayward names the Super Pump, Super II, MaxFlo and TriStar, and says to pick a pump rated between 30 and 100 GPM.
• Every size: set the platform level, somewhere that drains, and where the tank can empty by gravity. Keep the bump handle, the drain and the gauge where you can reach them.

All three manuals also say Hayward's pumps are for permanently installed pools, not storable ones, meaning pools built to be taken apart and packed away. If your above-ground pool comes down every fall, that matters before you buy a system.

Plumbing it

• Every connection is 1½ inch NPT. Use plastic male adapters, three turns of Teflon tape or a sealant made for ABS, then hand tight plus one full turn with a wrench. Hayward says more can damage the parts.
• Pipe: 1¼ or 1½ inch I.D. flexible pipe or hose, joined with insert fittings and stainless steel clamps.
• Unions at the suction and outlet ports are recommended, so the filter comes out for service and for winter.
• The gauge threads into the side of the body. If it isn't fitted, wrap its threads with Teflon tape first.
• The drain is a plug with a gasket. For a drain line, Hayward's optional ball valve, SP0723, takes 1½ inch pipe that slopes away from the filter.
• The handle can move to the other side of the outlet. Take off the grip and bump cover, tap the pivot pin out with a drift or a 10-penny nail, turn the handle, and tap the pin back in.

Starting it and pre-coating

1. Close the filter drain.
2. Open every suction and return valve. Hayward's caution is that starting the pump with any of them closed can cause serious injury or damage.
3. Open the vent valve under the bump cover, stand clear, and prime and start the pump. Close the vent once a steady stream of water comes out.
4. Pre-coat right away. The manuals say not to run the filter more than one minute without D.E.
5. Scoop the D.E. into the skimmer, as fast as the plumbing will take it: 4 lb on the EC40AC, 5 on the EC50AC, 6 on the EC65A and 7 on the EC75A.
6. Write down the gauge reading. Hayward calls it the pre-coat pressure, and every decision after this compares to it.

Use only a swimming pool grade of D.E. The manuals name two brands, or your pool store's own.

Bumping

When the gauge reads 7 to 10 psi above the pre-coat pressure, bump it:

1. Stop the pump.
2. Move the handle down slowly, then up briskly.
3. Do that three times.
4. Start the pump again.

Flow and pressure come back close to where they started. The starting pressure may creep up a little after each bump until the next full clean, and Hayward calls that completely normal.

• Vacuuming goes straight into the filter. Bump before and after. How to vacuum a pool covers the rest.
• During an algae bloom, Hayward says you may need to bump as often as every 2 to 3 hours.

Hayward's above-ground sell sheet says a charge of D.E. lasts four weeks.

Cleaning: bump, drain, recharge

Clean the filter when the pressure climbs more than 10 psi in under 24 hours, or when cloudy water comes back to the pool for more than 30 seconds after a bump.

1. Stop the pump and bump eight times.
2. Open the vent valve and the filter drain. If the filter sits below the pool's water line, close the suction and return valves first.
3. Let the water and dirt empty completely.
4. With the drain still open, run the pump for a few seconds to flush the bottom. Below the water line, open the suction valve for a few seconds with the pump off instead.
5. Close the drain and vent, open the valves, start the pump and let the filter fill.
6. Do the whole clean a second time.
7. Start it up and pre-coat as if it were new.

Where D.E. waste water can go is a local rule, and some places restrict it.

Once a year, soak the tubes

Minerals build up on the flex-tubes as water evaporates and chemicals go in, and eventually the filter cycles get shorter. Hayward suggests a yearly soak of the tube assembly in 20% muriatic acid mixed one to one with water, or a filter element cleaner used per its label, in a plastic container. Wear gloves and eye protection, then flush everything with cold water.

The troubleshooting table also gives a detergent clean: take the tube nest out, hose it down hard, soak it in a strong laundry detergent solution with warm water, and hose it again. The filter cleaning guide covers the rest of the equipment.

Four things clog the tubes, per Hayward:

• chemical deposits, faster if chemicals are fed through the skimmer
• running a charge too long with a lot of live algae in the pool
• running the filter without D.E.
• running it too long after start-up before adding D.E., including testing new plumbing with no D.E. in the filter

Opening the tank

Turn off the pump and open the vent valve to relieve the pressure before loosening anything. How the tank closes depends on the size.

EC40AC, two-bolt clamp. Center the clamp on the flange, and tap it with a rubber mallet or a block of wood if it's tight. On each bolt goes a washer and a spacer tube, then the bolt through both clamp halves, another washer and the nut, hand tight. Tighten the two bolts alternately with a ½ inch drive socket until the spacer tubes engage, then a quarter to half turn more.

EC50AC, spring clamp. The T-bolt goes through the trunnion, then the washer with the small hole, the spring, the washer with the large hole and the sleeve nut. Tighten the nut with a 9/16 inch socket until the spring coils all touch, then two full turns more. Hayward's warning is that not tightening it fully could cause serious injury or death.

EC65A and EC75A, 15 bolts. There's no clamp. The manual lists 15 tank bolts with 30 washers, which Hayward's site sells as the head bolt kit, but gives no procedure or torque for them.

To restart, open the valves, open the vent valve before starting the pump, stand clear, and close it once a steady stream of water comes out.

Two limits from the manuals:

• Never run or test the system above 40 psi on an EC40, or 50 psi on the EC50, EC65A and EC75A.
• Never purge the system with compressed air. Hayward says components can explode. Use only a high-volume blower at under 5 psi.

When D.E. gets back in the pool

Through the returns, the manuals give four causes:

• a tear in one or more flex-tubes
• a rip or hole in the diaphragm gasket
• a diaphragm gasket that's worn or fits loosely, which chemicals fed through the suction lines can speed up
• loose bolts on the tube sheets

Hayward's knowledge base adds too much D.E., cracked tube sheets and bad o-rings on the bump shaft.

Through the skimmer or main drain is a different fault: the built-in check valve, worn or stuck open. Clean it or replace it. D.E. in the pool covers how to tell the two apart.

The rest of the troubleshooting table

High pressure: normal dirt on the D.E., so bump it; too much D.E., so bump, drain and recharge; a small eyeball fitting restricting the return, so fit a larger one; or a partly closed return valve.

Less flow at the returns: the D.E. needs a bump or a clean, or the pump basket, skimmer basket or impeller is clogged, there's an air leak on the suction side, or the motor is running under speed.

Short cycles: the D.E. is loaded with dirt, the bump is being done wrong, the handle is bent, the pump puts out more than the filter's design flow, or there's algae. If short cycles continue after a proper bump, drain and recharge, the tubes are clogged and need cleaning.

Hard bumping: D.E. caked under the tube sheet, sometimes from suntan oil, hair and floating particles, so recharge more often and cut down on the oils; too much D.E. because the last dirty charge wasn't drained properly; or too long between bumps.

Very short cycles while vacuuming: normal with very dirty water or live algae. With alum or a flocculant in the pool, vacuum so the water bypasses the filter, because Hayward says floc clogs it.

Winterizing

Where freezing weather is expected, Hayward's instruction is to clean the filter, drain it, and take it indoors for the winter. That's what the unions are for. Closing a pool for winter covers the rest of the system.

Older Perflex filters

Hayward's parts diagrams still cover the models before the AC versions: the EC30, which takes 54 tubes, the EC40, and the EC50A. Their heads, bodies, bump shafts, gaskets and tube nests have their own numbers, and they're in the parts list below.

Check the prefix before you buy

• EC65A or EC75A from a dealer: Expert Line, three years parts and one year field labor.
• EC40AC or EC50AC, alone or as a system: Expert Line, two years parts, no labor.
• Any W3 version: Open Line, one year parts, no labor. Hayward approves Open Line products for sale online and in stores.

On all of them, the flex-tubes and o-rings are wear items, covered only for manufacturing defects. On a Perflex those are most of what wears out. Hayward also says it can refuse claims on anything bought from an unauthorized seller, including websites. The Hayward brand page explains the two lines.

Against the ProGrid

Hayward's other D.E. filter is the ProGrid, a vertical grid filter with a backwash valve.

• Cleaning: the Perflex bumps and drains; the ProGrid backwashes.
• Trigger: bump at 7 to 10 psi over pre-coat; the ProGrid backwashes at 8 to 10.
• Running dry: one minute on the Perflex; a minute or two on the ProGrid.
• D.E.: 4 to 7 lb across the four Perflex sizes, which is 0.175 to about 0.22 lb per square foot. The ProGrid is 0.125.
• Size: the Perflex tops out at 40 square feet; the ProGrid starts at 36 and goes to 72.
• Warranty: the same terms on the in-ground sizes.

Where Hayward's documents disagree

• The warranty. All three manuals print one year from the date of purchase. Hayward's product pages and its 2026 terms give two or three years, as above.
• The air relief at start-up. The manuals' Starting the Filter steps say to close the vent valve and let trapped air vent to the pool. Their own safety warnings, and the EC40 and EC50 steps for refitting the clamp, say to open the air relief before starting the pump and close it only once a steady stream of water comes out. This page follows the warnings.
• How many bumps. Regenerating is three times and cleaning eight. The troubleshooting table's fix for bumping incorrectly says to repeat six times.
• The two-bolt clamp. The EC40 and EC50 manuals say to tighten until the spacer tube engages, "approx. 100 in-lbs", then another quarter to half turn, also "approx. 100 in-lbs". Both steps can't be the same figure.
• The EC65A's turnover. Hayward's product pages give 25,920 gallons in 8 hours, which is 54 GPM, and 40,200 in 10 hours, which is 67 GPM. At 54 GPM, 10 hours is 32,400. The pages also label turnover in GPM rather than gallons.
• The pressure gauge. The product pages say no gauge is included. The manuals list one and tell you how to fit it if it isn't already installed. The gauge's number differs too: ECX2709A1 in the EC40 manual, ECX270861 on the EC40AC page, and ECX27091 in the other manuals, with ECX2712B1 also on the EC65A diagram.
• The EC50 clamp. Its manual covers a two-bolt plastic clamp and a spring clamp. Hayward's EC50AC diagram lists only the spring clamp, and the sell sheet calls it stainless.
• The pump sizes. Hayward's product titles give the systems 0.85 and 1.1 HP. Its 2023 sell sheet, and the systems' own web addresses, say 1 and 1.5 HP.
• Part numbers. The manuals and Hayward's current diagrams differ on the EC65A tube nest (ECX12515 against ECX1251), the tube sheets (sold singly in the manuals, as sets on the site), the flow controller (SPX1055 against ECX1055), the union and the cord set. This page lists both.
• Smaller details. Hayward's EC50AC pages give its width as 13.5 inches on the Expert Line page and 16 on the Open Line one. The EC40C80S system page gives its filter area as both 20 and 19 square feet. The sell sheet credits the longer warranty to a Totally Hayward partner; the product pages say a Hayward Rewards partner.