How to Clean a Hayward Pool Filter - Sand, Cartridge, and DE

Hayward Filter Lines - Which Do You Have?

Hayward makes four distinct filter families, each cleaned differently. Identifying your specific filter before doing any maintenance prevents mistakes. If your filter is a Pentair rather than a Hayward, see how to clean a Pentair pool filter for model-specific steps.

To find your exact model: Look for the label plate on the tank body. It is a metallic or printed label listing the model number, serial number, and specifications. If the label has faded, the shape of the filter and presence or absence of a bump handle will identify the family.

Once you know your filter family, jump to the relevant section below.

Hayward Pro Series Sand Filter - Backwashing Steps

The Pro Series is Hayward’s flagship sand filter line. The S180T (18” tank) handles pools up to 13,500 gallons; the S244T (24” tank) handles pools up to 28,200 gallons; the S311T (31” tank) handles pools up to 50,000 gallons. All use the same backwash procedure.

When to backwash: When your pressure gauge reads 8-10 PSI above your clean baseline. If your filter ran at 12 PSI when new and now reads 20-22 PSI, it is time.

Backwash procedure:

1. Turn off the pump. Never move the multiport valve with the pump running - the internal spider gasket will tear, causing immediate valve failure.
2. Set the multiport valve to BACKWASH. The Hayward Pro Series multiport has 6 positions: Filter, Backwash, Rinse, Recirculate, Waste, and Closed. On some newer models, there is also a Winterize position. Turn the handle firmly to BACKWASH until it clicks or seats.
3. Turn the pump on. Water now flows backwards through the sand bed.
4. Run until the sight glass water runs clear. The sight glass is a small transparent window on the multiport valve body. Water will initially appear brown or cloudy - run the backwash until it runs clear. This typically takes 2-3 minutes.
5. Turn the pump off.
6. Set the multiport to RINSE. This short cycle flushes the drain line and reseats the sand bed.
7. Run the pump for 30 seconds.
8. Turn the pump off. Set the multiport back to FILTER.
9. Restart the pump. Note the new clean baseline PSI.

S244T specific note: The 24” Pro Series tank holds 200 lbs of #20 silica sand and has a rated flow of 60 GPM. If you are replacing the sand, use only pool-grade #20 silica sand - not play sand, not construction sand, and not sand from a hardware store that does not specify #20 grade.

• Hayward Pro Series replacement sand on Amazon

Annual maintenance for Pro Series:

• Inspect and lubricate the multiport O-ring with Teflon-based pool lubricant (not petroleum grease, which degrades rubber)
• Inspect the spider gasket inside the multiport valve - cracks cause valve leakage between positions
• Check laterals at the bottom of the sand tank annually - cracked laterals allow sand to pass into the pool

Hayward SwimClear Cartridge Filter - Cleaning Steps

The SwimClear is Hayward’s primary cartridge line. The C3020 holds 300 sq ft of filtration area; the C4020 holds 400 sq ft (4 x 100 sq ft cartridges); the C4520 holds 450 sq ft; the C5020 holds 500 sq ft (4 x 125 sq ft cartridges). Larger models mean less frequent cleaning, but cleaning 4 cartridges at once takes more time.

Cartridge filters cannot be backwashed. They do not have a backwash port or multiport valve. Do not attempt to reverse flow through the filter - it will collapse the cartridge pleats. See our full guide on why cartridge filters cannot be backwashed for the complete explanation.

When to clean: When pressure gauge reads 8-10 PSI above your clean baseline.

Cleaning procedure:

1. Turn off the pump. Use the timer or breaker - not just the local switch.
2. Open the air relief valve. The air relief valve is a small screw or cock on the top of the filter body. Open it slowly and hold it open until the pressure gauge reads zero and air/water stops hissing out.
3. Remove the top plate. The SwimClear uses 6-8 stainless bolts around the top plate perimeter. Remove all bolts and set aside. Lift the top plate straight up - it may require a gentle rock to break the O-ring seal.
4. Lift out the cartridge elements. C3020 has 1 large cartridge; C4020, C4520, and C5020 have 4 cartridges. Note how they are oriented - some models use a core pipe that the cartridges thread onto.
5. Rinse each cartridge from top to bottom. Use a standard garden hose with a straight nozzle. Hold the nozzle parallel to the pleats and work systematically from the top pleat channel to the bottom, rotating the cartridge. The goal is to flush debris outward from the pleats, not to blast the fabric at high pressure. Do not use a pressure washer.
6. Chemical soak for deep cleaning. Once per month at minimum, soak cartridges overnight in enzyme-based cartridge cleaner diluted per label instructions. This dissolves oils, sunscreen residue, and calcium deposits that rinsing alone cannot remove.
   • Pool cartridge cleaner on Amazon
7. Rinse thoroughly after soaking. No residual chemical should remain before reinstallation.
8. Inspect each cartridge. Hold it up to bright light and look through the pleats. Pinholes or tears appear as bright spots. Check end caps for cracking or separation from the media.
9. Reassemble and restart. Lubricate the top plate O-ring with pool-grade Teflon lubricant before replacing the lid. Torque the bolts evenly in a cross pattern. Restart the pump, open the air relief valve to purge air, close when water flows steadily. Record new baseline PSI.

C5020 note: The 500 sq ft capacity means cleaning is needed less often than smaller filters, but you are rinsing and soaking 4 x 125 sq ft cartridges per session. Budget 60-90 minutes for a full chemical soak cleaning.

Finding replacement cartridges: The Hayward part number is printed on the end cap of your existing cartridge. Use this number for exact replacement. SwimClear C4020 replacement cartridges are Hayward part CX880XRE (set of 4).

• Hayward SwimClear replacement cartridges on Amazon

Hayward Pro-Grid DE Filter - Cleaning Steps

The Pro-Grid is Hayward’s standard DE filter line. The DE6020 (60 sq ft) is the most common residential model; the DE3600 (36 sq ft) suits smaller pools.

Routine maintenance - backwash and recharge:

DE filters are backwashed the same way as sand filters using the multiport valve. However, backwashing a DE filter removes the DE powder along with the trapped debris, so you must recharge with fresh DE after every backwash.

1. Backwash using the same procedure as the Pro Series sand filter (see above).
2. After returning the valve to FILTER and restarting the pump, immediately add fresh DE powder through the pool skimmer.
3. DE charge: 1 lb per 5 sq ft of filter area. DE6020 = 12 lbs. DE3600 = 7.2 lbs (round up to 7.5 lbs).
4. Add DE slowly through the skimmer, using a scoop or measuring cup. Do not dump all powder at once - it can clump before it reaches the filter.

• Pool-grade DE powder on Amazon

Annual teardown (required once per season):

Routine backwashing cannot remove all accumulated debris from DE grids. Once per year - typically at pool opening or closing - the filter requires full disassembly.

1. Turn off the pump. Backwash thoroughly to remove as much material as possible before opening.
2. Open the air relief valve and bleed pressure to zero.
3. Remove the multiport valve. Disconnect the plumbing unions on the valve inlet and outlet (do not use tools on the union collars - hand-tighten only when reassembling). Remove the valve mounting bolts and lift the valve off the tank.
4. Pull out the grid manifold assembly. The manifold is the central spine with individual flat grid panels hanging from it. Lift it straight out of the tank.
5. Hose off each individual grid panel. Remove grids one at a time from the manifold spine. Rinse the fabric surface thoroughly on both sides.
6. Inspect every grid for tears. Hold each grid up to bright light. Pinholes or tears are visible as bright spots in the dark fabric. A torn grid must be replaced immediately - DE powder bypasses a torn grid and enters the pool as white powder.
7. Clean the manifold. Brush the manifold spine and end cap with a stiff brush and hose clean.
8. Soak in DE filter cleaner solution. Place all grids and the manifold in a large bin with DE filter cleaning solution (such as Natural Chemistry Filter Perfect, diluted per label directions) for 2-4 hours. This removes the calcium and oil film that builds up on the grid fabric over a full season.
   • DE filter cleaner solution on Amazon
9. Rinse thoroughly. All chemical must be flushed before reassembly.
10. Reassemble. Reinstall grids onto manifold, lower manifold into tank, replace multiport valve (with fresh O-ring lubricated with Teflon pool lubricant), reconnect plumbing unions.
11. Prime and recharge. Restart pump, open air relief to purge air, then add the full DE charge through the skimmer.

Replacing torn grids: Hayward Pro-Grid replacement grids are model-specific. Note your filter model (DE6020 uses grids Hayward part DEX6020BX8 - a set of 8). Individual grids run $15-30 each.

• Hayward DE filter replacement grids on Amazon

Hayward Perflex DE Filter - The Bump Handle Difference

The Perflex is a distinctive Hayward DE filter that uses flexible “fingers” instead of rigid flat grids. The most identifiable feature is the bump handle protruding from the top of the tank.

How the bump handle works: As DE-coated fingers accumulate debris, a bump cycle redistributes the DE powder to expose fresh filtration surface. This extends the time between full cleanings significantly.

Bump procedure:

1. Turn off the pump.
2. Push the bump handle down firmly and rotate it - this agitates the fingers inside.
3. Bump 3-4 times.
4. Restart the pump.

This can restore normal operating pressure for additional weeks without a full cleaning. The EC40AC and EC65A1 are the most common models.

When bump cycles no longer restore pressure: Full cleaning is needed.

1. Backwash via the multiport valve (same procedure as sand or Pro-Grid).
2. Recharge with fresh DE through the skimmer (1 lb per 5 sq ft - EC65A1 = 65 sq ft = 13 lbs).
3. If pressure returns to baseline, resume normal operation.

Annual Perflex teardown:

1. Follow the same disassembly steps as Pro-Grid, but fingers are removed individually from a central manifold through the top opening.
2. Soak fingers in DE filter cleaner, rinse thoroughly, inspect each finger for tears.
3. Perflex replacement fingers are Hayward part EC65 or EC40 series (sold as sets).

• Hayward Perflex replacement fingers on Amazon

Hayward Filter Parts to Keep On Hand

Having common replacement parts on hand prevents a service interruption. These are the items that wear most frequently across Hayward filter lines.

• Hayward filter parts on Amazon
• Pool-grade Teflon lubricant for O-rings on Amazon

Related Guides

• How to Backwash a Pool Filter - Complete Guide
• How to Backwash a Hayward Pool Filter - Detailed Steps
• How Much DE to Add to a Pool Filter
• When to Replace a Pool Filter Cartridge