Rank #10 in Best Aquarium Filter 2026: Turnover Is the Only Number
OsAtNb Quiet 4in1 Internal Aquarium Filter, 500 L/H
Price and rating as shown on Amazon when we collected them. Both change.
The OsAtNb 4-in-1 is a 500 L/H internal filter for £19.99, with 3.8 stars from 888 ratings and 20 per cent one-star — one in five buyers.
It takes tenth because its listing is internally inconsistent in three ways, and because a fifth of its owners giving it one star is a record rather than a complaint. The specification looks good and the reviews do not agree.
How those 888 ratings break down
An average hides its own shape. This is the spread behind the 3.8 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Ratings | 3.8 from 888 |
|---|---|
| Tank range | 200L in the title, 180L in a bullet |
| Wattage | 6 W labelled as horsepower |
| Maximum flow | 500 litres per hour |
| Outlets | Three types |
| Price | £19.99 |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“Brilliant, super powerful, and extremely quiet”
Verified purchase“The media could not be loaded. Works alright I’ve just set up a tank and will see how I get on once fish is inside.”
What it is up against
The rivals it was ranked against in Best Aquarium Filter 2026: Turnover Is the Only Number.
Rank #1
Fluval U2 Internal Aquarium Filter, Up to 110 Litres, 400 L/H Adjustable
£36.00
Rank #2
NICREW Magi700 Fish Tank Filter, 700 L/H for 60-150L Tanks
£19.99
Rank #3
Interpet PF1 Internal Power Filter, for Aquariums Up to 68 Litre
£15.69
Rank #4
NICREW Magi Mini Fish Tank Filter, 150 L/H for 20L Tanks
£13.99
Questions people ask
Why is it last?
One in five of its 888 ratings is one-star, which is 178 buyers, and the listing contradicts itself on tank size and units.
Is the horsepower rating real?
No: the field is labelled horsepower and contains 6 watts, which is 0.008 horsepower.
What tank size is it for?
The title says 20 to 200 litres and a bullet says 20 to 180. At 200 litres, 500 L/H is 2.5 turnovers an hour, below the recommended range.
Does it work?
Plenty of reviewers say it is powerful and quiet; the concern is how long it lasts, which is what the one-star comments describe.
Why not buy it anyway?
For £4 more the NICREW Magi700 publishes a coherent flow and tank range, a spare impeller and a one-year warranty.
How many ratings does it have?
888 at the time of collection, averaging 3.8 stars, with 57 per cent five-star and 20 per cent one-star.
Comments
Reader comments are not checked against the manufacturer's claims above.
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