The Aqua One Ocellaris 400 takes the Aqua One Sponge 143s (25143S) for Ocellaris 400 as its filter media; Australian sellers list it from A$10.88 as of 30 October 2026. Fitment confirmed against the manufacturer's compatibility list.
Your aquarium filter
Aqua One Ocellaris 400
Aquarium filter
Confirmed against Aqua One's listConfirmed against Aqua One's own compatibility list
Not yours? Change
Takes the 25143S filter media
Sponge 143s (25143S) for Ocellaris 400 · 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 25143S
Filter media · check the code on your old filter.
Other Aqua One aquarium filters and their replacement media
The 25143S fits the Ocellaris 400 only. These Aqua One models take a different filter media:
GenuineGenuine Aqua One
$10.88
Aquarium Spare Parts · 30 OctLowest genuine · Aquarium Spare Parts · checked 30 Oct
CompatibleCompatible option
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No compatible seller tracked yetNo compatible seller tracked yet
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 · $10.88
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This aquarium filter also takes a fine pad
- Aqua One Wool 143w (25143W) for Ocellaris 400Open Aquarium Spare Parts$6.94 each · 2-pack $13.88
Separate from the filter media. Reduces micro-particles (fine wool, mechanical).
Compare 1 seller
AUD, before delivery. Each price shows when it was checked.
Opens Aquarium Spare Parts in a new tab. Their page is the source of truth for price, delivery and returns.
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 Ocellaris 400
Watch the guide or follow the steps.
No clear video for this part yet. The steps cover it.
- 1Turn the canister filter off at the power point and unplug it. Close the taps or flow valve and disconnect the tap connector from the head unit (Nautilus: lift the locking lever).
- 2Fill a bucket with water from your aquarium. Release the clips, lift off the head unit and take the media baskets out of the canister.
- 3Take out the sponges and the white wool. Dunk the baskets of biological media a few times in the bucket of aquarium water: Aqua One says this keeps the chlorine in tap water from killing the good bacteria on it.
- 4Rinse the sponges in the bucket of aquarium water. Fit a new sponge once the old one clogs and water no longer passes through it easily.
- 5Put the media back in the same baskets and order, refit the baskets and head unit, then prime and restart the filter as its manual describes.
Every number this part goes by
- Retail name:
- 143S
- Retail name:
- 25143S
Sellers list any of these; they are the same part.
About your Aqua One Ocellaris 400
Aqua One aquarium filter — Ocellaris canister filter. Its filter media is the Sponge 143s (25143S) for Ocellaris 400, part 25143S.
Also in this aquarium filter: Aqua One Wool 143w (25143W) for Ocellaris 400.
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 Ocellaris 400?
- The Aqua One Ocellaris 400 takes the Aqua One Sponge 143s (25143S) for Ocellaris 400.
- Where can I buy the 25143S in Australia?
- We track 1 Australian seller for the 25143S; the lowest listed price when we last checked was A$10.88 at Aquarium Spare Parts. Prices are re-checked daily and dated on this page.
- How do I fit the 25143S in an Aqua One Ocellaris 400?
- 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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