Astralpool ZX 50 & ZX 75 Filter Tank Body 78380/7821102

Astralpool ZX 50 & ZX 75 Cartridge Filter Tank Body — 7821102 / 78380 (also Zodiac ZXC / ZCF, Astral SMART, Filtrite CF, Aquatight)

This is the genuine Astralpool tank body for the ZX 50 and ZX 75 cartridge filter, part number 7821102 (older number 78380). It is the lower pressure vessel that holds the cartridge element — supplied on its own, to replace a tank that has cracked, split, crazed or is leaking below the lid. One tank moulding serves both the ZX 50 and ZX 75; the two differ in filtration area, not element size.

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

This is the same filter sold under several brands — Astralpool ZX, Hurlcon ZX, Zodiac ZXC, Zodiac ZCF / Titan ZCF, Astral Leisure SMART, Filtrite CF and Aquatight. The Zodiac ZXC is simply the Zodiac-badged Astralpool ZX. Tank colour and part number have both changed across production runs, so confirm the model and element size before ordering.

The ZX Body Match Rule (rev. ZXB-1.0)

A tank body is sized to the filter model, not to the plumbing, so match it by model badge and confirm with a measurement:

1. Find the model number on the filter label, or moulded into the lid or tank. It reads ZX — or the Zodiac ZXC / ZCF, Astral SMART or Filtrite CF — followed by a number.
2. This body, part 7821102, is the correct tank for the ZX 50 / ZXC 50 and ZX 75 / ZXC 75 only.
3. Confirm physically: pull the cartridge element and measure it. The 50 and 75 both take a short 290mm-long × 230mm-diameter element.
4. If your badge reads 50 or 75 in any of those ranges and your element is the short 290mm length, this is your body. A different size number, or a longer element, needs a different tank — see the chooser below. Note: Astralpool XC is a separate, unrelated series and does not use this tank.

Worked Example

A customer at Torquay has a filter with a chalky, unreadable label, but the moulding on the tank shoulder reads ZX75. They pull the element: it measures 231mm across the end cap and about 288mm tall — the short element. Badge says ZX75, element is the 290mm length — so this 7821102 body is correct. They order the body with a new tank O-ring (78110) and a fresh 75 sq ft element, because a tank old enough to split usually sits on a flattened O-ring and a tired element.

Which Tank Body Do I Need?

Will Not Fit — Order The Correct Tank Instead

• ZX100 / ZX150 (ZXC100/150) — taller tank for the longer element. Use the ZX100/150 body (7821202).
• ZX200 / ZX250 (ZXC200/250) — taller tank again. Use the ZX200/250 body (7821302).
• ZX310 — twin-element tank with an element coupler. Use the ZX310 body (7821702).
• Astralpool XC — a separate, unrelated filter series. The XC tank is not interchangeable with the ZX / ZXC tank despite the similar name. Contact us with your model and a photo.
• Hurlcon QX — a different filter with a 222mm lid, not part of the ZX family.

Compatible Filters — 50 & 75 Sizes

This 7821102 tank body serves the 50 and 75 size in each of these — all the same filter under different badges:

• Astralpool ZX / Hurlcon ZX: ZX50, ZX75
• Zodiac ZXC: ZXC50, ZXC75
• Zodiac ZCF / Titan ZCF: ZCF75
• Astral Leisure SMART: SMART 350, SMART 550
• Filtrite CF: CF50, CF75
• Aquatight: cartridge filters built on the ZX 50 / 75 tank

Matching cartridge elements: 50 element — 78095 (290mm × 230mm) · 75 element — 78096 (290mm × 230mm).

What's Included

• ZX / ZXC 50 / 75 filter tank body (lower pressure vessel), part 7821102 (78380)

Not included: lid assembly, tank O-ring, cartridge element, pressure gauge and plumbing unions are separate items. Fit a new tank O-ring whenever you replace a tank — the old seal has taken a set to the old tank's sealing face.

Measurements & Identification

• Fits models: ZX50 / ZXC50, ZX75 / ZXC75 (and ZCF75, SMART 350 / 550, Filtrite CF50 / CF75)
• Element: short 290mm long × 230mm diameter
• Part number: 7821102 (older 78380; supplied as SP7821102)

Symptoms Of A Failed Tank

• A crack, split or weep low on the tank body, below the lid seal
• Water tracking down the outside of the tank when the pump runs
• Crazing or brittleness in the moulding from years of UV exposure
• A tank that has been over-pressurised, distorted or impact-damaged

Fitting Notes & Safety

• These are pressure vessels. Never work on the filter with the pump running or the system pressurised. Shut down, isolate power, close valves and release all pressure at the air bleed before you start.
• Transfer your fittings — drain cap, union tails and any bulkhead fittings — to the new tank, renewing their O-rings.
• Fit a fresh tank O-ring and lubricate it with a silicone-based lubricant only. Petroleum grease swells and destroys the seal.
• Hand-tighten the locking ring only. Over-tightening is what cracks lids and rings — and a fresh tank deserves a fresh start.
• On recommissioning, open the air bleed until water flows steadily, close it, and note the clean starting pressure on the gauge. Clean the element when pressure climbs 15–20 kPa above that figure.

Related ZX / ZXC Filter Parts

• ZX / ZXC lid assembly with handles & locking ring — SP7820502
• ZX / ZXC tank O-ring (lid seal) — 78110 / 78105
• ZX / ZXC air bleed plug & O-ring
• Full Astralpool ZX / Zodiac ZXC cartridge filter range & spare parts

Part Numbers & Search References

This tank body: 7821102 · 78380 · SP7821102 · Body Only ZX50-75 · Astralpool ZX50 tank · ZX75 tank · Zodiac ZXC50 / ZXC75 filter body · Hurlcon ZX filter body · Zodiac ZCF75 tank · Filtrite CF50 / CF75 body · SMART 350 / 550 filter body · Aquatight ZX tank · ZX cartridge filter housing · Astral pool filter tank replacement.

Frequently Asked Questions

Does this body fit both the ZX50 and the ZX75?
Yes. Astralpool used one tank moulding, part 7821102, for both the ZX50 and the ZX75. The two models differ in filtration area, but run the same short element in the same body.

How do I know I have a 50 or 75 and not another size?
Read the model number on the filter label or moulded into the lid or tank. If it reads ZX50, ZX75, ZXC50, ZXC75, ZCF75, Filtrite CF50, CF75, SMART 350 or SMART 550, this body is correct. Any other number needs a different tank.

My filter is a Zodiac ZXC. Is this the right body?
Yes. The Zodiac ZXC is the same filter as the Astralpool ZX, just Zodiac-badged. If it reads ZXC50 or ZXC75, this 7821102 body is correct.

My filter is an Astralpool XC. Is this the right body?
No. The XC is a separate, unrelated filter series and does not share the ZX / ZXC tank body. Contact us with your model and a photo and we will match the correct part.

Does the body come with the lid, O-ring or element?
No. The tank body is supplied on its own. The lid assembly, tank O-ring and cartridge element are separate items, all linked on this page. Fit a new O-ring whenever you replace a tank.

The ZX range is discontinued. Can I still get this body?
Yes. The ZX filter range has been superseded, but the serviceable parts including this tank body are still available. Replacing a tank on an otherwise sound filter is far cheaper than a whole new unit.

Is this a genuine Astralpool part?
Yes. This is the genuine Astralpool tank body, part 7821102 (older 78380). It is a special-order item.

Why would I replace the tank body rather than the whole filter?
A cracked or leaking tank is usually the only failed component. If your lid, ring, gauge and plumbing are sound, replacing just the body restores the filter at a fraction of the cost of a new one.

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

As with all products, these must be diagnosed and fitted by a qualified and experienced person. This is a special-order item.