The Aqua One Arc 16 takes the Aqua One Sponge 185s (25185S) for Arc 16 as its filter media; Australian sellers list it from A$9.88 as of 29 October 2026. Fitment confirmed against the manufacturer's compatibility list.
Your aquarium filter
Aqua One Arc 16
Aquarium filter
Confirmed against Aqua One's listConfirmed against Aqua One's own compatibility list
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Takes the 25185S filter media
Sponge 185s (25185S) for Arc 16 · check the code printed on your old filter before ordering.
Your aquarium filter
Aquarium filter
Confirmed against Aqua One's listConfirmed against Aqua One's own compatibility list
Takes the 25185S
Filter media · check the code on your old filter.
Other Aqua One aquarium filters and their replacement media
The 25185S fits the Arc 16 only. These Aqua One models take a different filter media:
GenuineGenuine Aqua One
$9.88
Aquarium Spare Parts · 29 OctLowest genuine · Aquarium Spare Parts · checked 29 Oct
CompatibleCompatible option
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Genuine: made by Aqua One. Compatible: another brand.Genuine is made by Aqua One. Compatible is made by another brand. Check the seller's page for the size and models it fits.
Lowest price · $9.88
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Other parts this aquarium filter takes
- Aqua One Ceramic Cartridge 102c (25102C)Open Aquarium Spare Parts$18.88
The biological media. Separate from the filter media. Reduces ammonia and nitrite, via the bacteria that live on it (biological media).
- Aqua One Carbon Cartridge 1c (25001C)Open Aquarium Spare Parts$9.44 each · 2-pack $18.88
The carbon filter. Separate from the filter media. Reduces dissolved waste, odours and discolouration (activated carbon). Replace every 2 months.
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AUD, before delivery. Each price shows when it was checked.
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How long it lasts
Replace it when it clogs, breaks down or no longer holds its shape, Aqua One says; until then rinse it in a bucket of aquarium water each time you clean the filter.
How to change the filter media in your Aqua One Arc 16
Watch the guide or follow the steps.
No clear video for this part yet. The steps cover it.
- 1Unplug all the aquarium's equipment, then lift off the light unit and lid and put them somewhere safe.
- 2Open the filter compartment and take out the sponge and the cartridges (carbon, and ceramic if your tank has one).
- 3Take some water out of the aquarium and rinse the sponge and cartridges in it. Aqua One says never to rinse the sponge under the tap, as that kills the beneficial bacteria. If needed, siphon waste out of the filter chambers.
- 4Put the sponge back, or fit a new one once the old one blocks up or breaks down.
- 5Refit everything, replace the lid and light unit, check your hands and plugs are dry, then turn the power back on and check the equipment over the next half hour.
Every number this part goes by
- Retail name:
- 185S
- Retail name:
- 25185S
Sellers list any of these; they are the same part.
About your Aqua One Arc 16
Aqua One aquarium filter — Arc aquarium. Its filter media is the Sponge 185s (25185S) for Arc 16, part 25185S.
Also in this aquarium filter: Aqua One Ceramic Cartridge 102c (25102C), Aqua One Carbon Cartridge 1c (25001C) (every 2 months).
Where the model number is: The model is on the filter's lid, motor head or a label on its side (Fluval 307, Eheim Classic 2215). For a tank with a built-in filter, use the tank's name.
Fits this Aqua One model
Aqua One1 model
Common questions
- Which filter media fits the Aqua One Arc 16?
- The Aqua One Arc 16 takes the Aqua One Sponge 185s (25185S) for Arc 16.
- Where can I buy the 25185S in Australia?
- We track 1 Australian seller for the 25185S; the lowest listed price when we last checked was A$9.88 at Aquarium Spare Parts. Prices are re-checked daily and dated on this page.
- How do I fit the 25185S in an Aqua One Arc 16?
- No tools, a few minutes: 5 steps, listed on this page with the replacement video where the maker has one.
- What happens if I don't change it?
- Spent carbon stops removing odours and discolouration, and clogged pads slow the flow, so the filter moves less water through the tank.
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