The AstralPool QL420 takes the AstralPool Viron QL420 cartridge element 78079 as its cartridge; Australian sellers list it from A$90.00 as of 28 October 2026. Fitment confirmed against the manufacturer's compatibility list.
Your pool filter
AstralPool QL420
Pool filter
Confirmed against AstralPool's listConfirmed against AstralPool's own compatibility list
Not yours? Change
Takes the 78079 cartridge
Viron QL420 cartridge element 78079 · check the code on your old part before ordering.
This filter takes 4 cartridges.
Your pool filter
Pool filter
Confirmed against AstralPool's listConfirmed against AstralPool's own compatibility list
Takes the 78079
Cartridge · check the code on your old part.
This filter takes 4 cartridges.
Other AstralPool pool filters and their cartridges
The 78079 fits the QL420 only. These AstralPool models take a different cartridge:
GenuineGenuine AstralPool
$174.00
Heater and Spa Parts · 28 OctLowest genuine · Heater and Spa Parts · checked 28 Oct
CompatibleCompatible option
$90.00
Heater and Spa Parts · 28 OctHeater and Spa Parts · checked 28 Oct
Check sellerCheck seller details
Genuine: made by AstralPool. Compatible: another brand.Genuine is made by AstralPool. Compatible is made by another brand. Check the seller's page for the size and models it fits.
Lowest compatibleLowest compatible price · $90.00
Heater and Spa Parts. Compare with genuine below. Some links earn us a commission. Some seller links earn us a commission, at no extra cost to you.
Compare 4 listings from 3 sellers
AUD, before delivery. Each price shows when it was checked.
Compatible options
3 sellers
Opens Heater and Spa Parts in a new tab. Their page is the source of truth for price, delivery and returns.
How long it lasts
Replace it when cleaned elements still read 27–41 kPa (4–6 psi) above the new-filter pressure, or are damaged; check once a year.
After replacing: No reset light. Note the gauge reading with clean elements; AstralPool says to clean them when the gauge rises 20 kPa.
How to change the cartridge in your AstralPool QL420
Watch the guide or follow the steps.
No clear video for this part yet. The steps cover it.
- 1Turn the pump off and release the pressure: open the air bleed and close the valves. Never loosen the clamp band while the system is under pressure.
- 2Undo the clamp band and lift the filter lid off the lower body.
- 3Lift the top manifold off the four elements, then lift each element out.
- 4Hose each element off without damaging the pleats, or fit new ones.
- 5Refit the manifold into all four elements and the internal pipe, lower the lid on (keep the O-ring in place) and refit the clamp band before restarting.
Every number this part goes by
- Retail name:
- 78079
- Retail name:
- SP78079
Sellers list any of these; they are the same part.
About your AstralPool QL420
AstralPool pool filter — Viron QL cartridge filter. Its cartridge is the Viron QL420 cartridge element 78079, part 78079.
Where the model number is: The model is on the label on the filter tank or under the lid (Zodiac CS150, Hayward C150S). On an above-ground pump it is on the pump's label or the box (Intex model 604 or item 28604, Bestway 58383); on an inflatable spa, on the box or the pump unit's label (Lay-Z-Spa Miami, Intex SB-H20). If the label has worn off, measure the old cartridge's length and diameter.
Fits this AstralPool model
AstralPool1 model
This filter takes 4 cartridges.
Common questions
- Which cartridge fits the AstralPool QL420?
- The AstralPool QL420 takes the AstralPool Viron QL420 cartridge element 78079. This filter takes 4 cartridges.
- Where can I buy the 78079 in Australia?
- We track 3 Australian sellers for the 78079; the lowest listed price when we last checked was A$90.00 at Heater and Spa Parts. Prices are re-checked daily and dated on this page.
- How do I fit the 78079 in an AstralPool QL420?
- 5 steps, listed on this page with the replacement video where the maker has one.
- What happens if I don't change it?
- A clogged cartridge slows the flow and the pump works harder, and a torn one lets dirt back into the water, so the pool or spa clouds.
- Is there anything to reset afterwards?
- No reset light. Note the gauge reading with clean elements; AstralPool says to clean them when the gauge rises 20 kPa.
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