Astralpool ZX / Zodiac ZCF Titan / Filtrite CF / Aquatight / Smart Filter Lid with Handles & Locking Ring

Genuine Astralpool / Hurlcon ZX / Zodiac ZCF Cartridge Filter Lid Assembly with Locking Ring

Genuine Astralpool / Hurlcon ZX cartridge filter lid assembly, supplied complete with locking ring, handles and air bleed assembly. Current manufacturer part number SP7820502. This is the factory replacement lid used on Astralpool ZX, Hurlcon ZX, Zodiac ZCF / Titan ZCF, Astral Leisure Pools SMART, Filtrite CF, Aquatight and selected re-branded cartridge filters built on the ZX-style lid and tank design.

• Physically Stocked, unlike most "drop-shipping" websites.
• Shipped from VIC, NSW, WA, QLD

Use this lid assembly to replace a cracked, sun-perished, leaking or hard-to-tighten filter lid. These filters have been sold under several brand names across more than two decades, and both the lid colour and the part number have changed across production runs, so always check the model and physical size before ordering.

Quick Fit Check — 290mm Lid

The ZX-style lid measures 290mm across the lid / locking ring. If your existing lid measures roughly 290mm, this is almost certainly the correct assembly. If it measures around 222mm you have the smaller Hurlcon QX lid, which is a different part and will not fit. Measure across the widest point of the moulded lid, not the tank rim.

What's Included

• Complete cartridge filter lid top
• New locking ring (lock nut)
• Lid handles and handle screws, factory fitted
• Air bleed assembly
• Air bleed O-ring

Important — supplied as an assembly only: Astralpool and Zodiac do not supply the lid top and the locking ring as separate service items on this filter family. The complete lid assembly is the only genuine replacement path. If you have been quoted a "lid only" or "lock ring only" part elsewhere, it is either old superseded stock or a non-genuine copy.

Colour note: These lids have previously been supplied in grey, graphite, beige and black depending on age and brand. Current production is black. Colour may differ from the original lid fitted to your filter — the fit, thread and sealing surfaces are unchanged.

Does not include the large tank body O-ring. The main lid-to-tank O-ring (part 78105, also referenced as 78110) is a separate item. If your lid and locking ring are still sound and the filter is only weeping at the seal, you likely need the O-ring alone — see the link further down this page.

Compatible Models & Matching Filter Elements

Each model below links to the matching replacement cartridge element we stock. Our elements are Darlly aftermarket — OEM-equivalent media and end caps built to the original dimensions, not genuine Astralpool branded stock. Most customers replacing a lid are due for an element at the same time.

Astralpool / Hurlcon ZX Series cartridge filters:

• ZX50 / ZX 50 — 50 sq ft, 4.75 m², 225 L/min — element 78095 replacement (290mm x 230mm)
• ZX75 / ZX 75 — 75 sq ft, 7.00 m², 290 L/min — element 78096 replacement (290mm x 230mm)
• ZX100 / ZX 100 — 100 sq ft, 9.40 m², 375 L/min — element 78097 replacement (495mm x 230mm)
• ZX150 / ZX 150 — 150 sq ft, 14.00 m², 445 L/min — element 78098 replacement
• ZX155 / ZX 155 — element 78088 replacement, supplied as a pair
• ZX200 / ZX 200 — 200 sq ft, 19.00 m², 490 L/min — element 78099 replacement (688mm x 230mm)
• ZX250 / ZX 250 — 250 sq ft, 24.00 m², 515 L/min — element 78094 replacement (688mm x 230mm)
• ZX310 / ZX 310 — 310 sq ft, 545 L/min — element 78088 replacement, supplied as a pair (joined with element joiner 78078)

Zodiac ZCF / Titan ZCF cartridge filters:

• ZCF75 / ZCF 75 — uses the ZX75 / ZCF75 element
• ZCF100 / ZCF 100 — uses the ZX100 / ZCF100 element
• ZCF150 / ZCF 150 — uses the ZX150 / ZCF150 element
• ZCF200 / ZCF 200 — uses the ZX200 / ZCF200 element

Astral Leisure Pools SMART cartridge filters:

• SMART 350 / Smart 350 — uses the ZX75 / Smart 350 element
• SMART 450 / Smart 450 — uses the ZX150 / Smart 450 element
• SMART 550 / Smart 550 — uses the ZX75 / Smart 550 element

Also commonly cross-referenced with selected re-branded ZX-style filters, including:

• Filtrite CF50 / CF 50
• Filtrite CF75 / CF 75
• Filtrite CF100 / CF 100
• Filtrite CF150 / CF 150
• Filtrite CF200 / CF 200
• Filtrite CF250 / CF 250
• SpaPro X50 / X 50
• SpaPro X100 / X 100
• SpaPro X150 / X 150
• SpaPro X200 / X 200
• WWDG CF100 / CF 100
• WWDG CF150 / CF 150
• WWDG CF200 / CF 200
• Aquatight cartridge filters using the ZX-style tank
• Astral IX / IX50 inline leaf canisters where the same ZX-style lid assembly is used

Will not fit: Hurlcon QX (222mm lid), Hurlcon CL, Astral GX, Zodiac CF / Emaux / Waterlinx / Magnaflow cartridge filters, Astralpool XC. These use different lid diameters and thread forms despite similar appearance.

Part Numbers, Superseded Numbers & Search References

Current part number: SP7820502

Superseded and legacy numbers this assembly replaces:

• 7820502 / SP 7820502
• SP7848210 / 7848210
• SP7848110 / 7848110
• 7820510
• 7820102 (lid top only — no longer supplied separately)
• APA302685 / APA_302-685

Common search terms: Astralpool ZX filter lid, Hurlcon ZX filter lid, Zodiac ZCF filter lid, Titan ZCF filter lid, Astral SMART filter lid, Filtrite CF filter lid, ZX cartridge filter lid and locking ring, ZCF cartridge filter lid and locking ring, ZX filter lid with handles, 290mm pool filter lid, Astral pool filter lock ring.

Complete ZX Cartridge Filter Spare Parts Reference

Taken from the Astralpool spare parts catalogue for the ZX cartridge filter, for cross-referencing while you have the filter apart:

• Complete lid assembly — SP7820502 (this item)
• Lid O-ring (tank seal) — 78105 / 78110
• Lid handles — 7820202 (×2)
• Handle screws — 40218 (×4)
• Air bleed / drain plug — 78705 / 7870510 (older references 78205, 78207)
• Air bleed & drain plug O-ring — 78103
• Pressure gauge with cover — 75043
• Filter body ZX200 / ZX250 — 7821302
• Filter body ZX310 — 7821702
• Element joiner, ZX310 only — 78078
• Blanking cap 50mm — 78214
• Blanking cap with drain — 78218
• Glue-in threaded pipe fitting — 950923
• Union O-ring — 70003
• 50mm glue-in union tail — 950920 | 40mm glue-in union tail — 950918
• Union lock nut — 950919
• Complete 40mm union — 10649 | Complete 50mm union — 10650
• Component bag — 78328
• Instruction manual — INST247

Why Replace The Filter Lid?

• Replace a cracked, sun-damaged or brittle lid
• Fix leaks from the lid or locking ring area
• Restore correct sealing and filter pressure
• Replace a damaged, cross-threaded or hard-to-tighten locking ring
• Replace snapped or missing lid handles that make the ring impossible to undo
• Reduce the chance of air being drawn into the filtration system
• Help prevent unsafe operation of a damaged pressurised filter

ZX-family lids are a wear item in Australian conditions. UV exposure, chlorine vapour inside the tank and repeated over-tightening all embrittle the moulding over time. A lid that has started to craze, or a locking ring that grinds rather than turns smoothly, is on borrowed time — these are pressure vessels and a lid failure under pressure is not a small event.

Fitting Notes & Safety

• Never loosen the locking ring while the pump is running. Shut the pump down, isolate power, close any valves and release all pressure via the air bleed before touching the lid.
• Wind the air bleed open and confirm the pressure gauge reads zero before undoing the ring.
• Clean the tank rim, the O-ring groove and the ring threads thoroughly. Grit in the threads is the single most common cause of a lid that will not seat.
• Lubricate the tank O-ring with a silicone-based lubricant only. Petroleum jelly and mineral greases attack the rubber and swell the seal.
• Hand tighten the locking ring only. Do not use a strap wrench, lever bar or hammer — over-tightening is what destroys most rings and lids.
• On start-up, open the air bleed two to three turns until water flows steadily, then close it. Note the clean starting pressure on the gauge.
• Clean the element when pressure rises 15–20 kPa above that clean starting figure, or when return flow drops off.

ZX-series tanks are rated to a maximum working pressure in the 250–300 kPa range depending on model and revision. If your gauge is sitting anywhere near that, stop and diagnose the restriction before running the filter.

Need The Large Tank O-Ring?

This lid assembly does not include the large tank body O-ring. If your existing lid and locking ring are still serviceable but the filter is leaking around the seal, you may only need the O-ring. It is good practice to fit a new tank O-ring whenever you fit a new lid — the old seal has taken a set to the old lid's sealing face.

Click here for the Astralpool / Hurlcon ZX cartridge filter tank O-ring.

Click here for the replacement air bleed plug and O-ring.

Click here for the full Astralpool ZX cartridge filter and spare parts range.

Frequently Asked Questions

Can I buy just the locking ring, or just the lid?
No. Astralpool and Zodiac only supply this as a complete lid assembly. The lid, ring, handles and air bleed come together under SP7820502.

My old lid is beige or grey and this one is black. Will it still fit?
Yes. Colour has changed several times across production runs. The moulding, thread and sealing dimensions are unchanged. Current production is black.

Does this fit the Zodiac ZCF / Titan ZCF?
Yes. The Zodiac ZCF and the Astralpool ZX share the same lid and tank architecture, which is why the same assembly services both ranges.

Are the replacement elements genuine Astralpool?
No. This lid assembly is a genuine Astralpool part, but the cartridge elements we link to are Darlly aftermarket — built to the original dimensions with equivalent media, at a lower price than branded stock. If you specifically need genuine Astralpool elements, contact us and we can quote them.

My ZX filter is discontinued — can I still get parts?
Yes. The ZX range itself has been superseded, but the serviceable parts including this lid assembly, elements, O-rings and gauges are still available. Replacing a lid on an otherwise sound tank is far cheaper than replacing the filter.

Do I need a new tank O-ring at the same time?
Strongly recommended. The old O-ring has conformed to the old lid's sealing face and is the usual reason a brand new lid still weeps.

How do I know if mine is a ZX-style lid?
Measure the lid across its widest point. ZX-style is approximately 290mm. The Hurlcon QX is approximately 222mm and is a different part entirely.

Check Before Ordering

Because these filters were sold under different brands, model names and colours, compare the shape of your existing lid, locking ring and filter body before ordering, and confirm the 290mm measurement. If you are unsure, send us a photo of the filter label, lid and tank and we can help confirm the correct part. We would rather spend two minutes checking than have you fit the wrong lid to a pressurised vessel.

Manufacturer Catalogues, Diagrams & Part Numbers

Need exploded views, spare part numbers, product numbers, diagrams, or more product information? See the manufacturer catalogues: Astralpool Catalogue 2026 | Zodiac Catalogue 2026