Rank #2 in Best Fish Tank 2026: 10 Ranked, £99.99 Buys 20 or 54 Litres
Fluval Flex 2.0 Aquarium Kit, 57 L, Black
Price and rating as shown on Amazon when we collected them. Both change.
The Fluval Flex 2.0 Black Aquarium Kit 57 L comes in at number two in this guide, and it is the one tank here priced above the £99.99 trio: £129.99, thirty pounds more than the cheapest of them, for 57 litres. Put another way, this listing works out at roughly £2.28 per litre, while the 20-litre tank sold at £99.99 in the same set works out at about £5.00 per litre. On the numbers in the ads alone, the extra £30 here buys water rather than a badge.
The figure that separates this listing from the rest of the set is the weight. The specification table gives an item weight of 13.2 kg for a 57-litre aquarium measuring 41.5 x 40 x 39 cm — a weight that could plausibly belong to a glass tank sitting on a shelf. Two other listings in this guide give 200 g for a 60-to-70-litre tank and 136 g for a 20-litre one, which cannot be the tank itself. The Fluval listing carries its own loose end, too: the star breakdown supplied with it adds up to 100 ratings while the same listing states 55 ratings, and its Special Features field reads 'Weather Resistant' on a table that also says the tank is for Indoor use. Everything on this page is taken from the Amazon listing as written; we have not tested or measured this tank ourselves.
How those 55 ratings break down
An average hides its own shape. This is the spread behind the 4.6 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £129.99 |
|---|---|
| Rating | 4.6 out of 5 from 55 ratings |
| Tank Volume | 57 litres |
| Item Dimensions | 41.5 x 40 x 39 cm (L x W x H) |
| Item Weight | 13.2 kg |
| Included Components | Circulation pump, glass aquarium, LED light, power supply, spray bar |
| Best Sellers Rank | 11,788 in Pet Supplies; 5 in Aquariums |
| Special Features (as listed) | Weather Resistant |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“Had this for a couple of months now, and very pleased with the tank. Filtration system is quality and easy to maintain. Lighting works well too. It's the right size for what we needed for the living room.”
Verified purchase“Beautiful tank, well made, good size for beginners, easy access to the filters when needed, good value for starter kit. Thank you”
What it is up against
The rivals it was ranked against in Best Fish Tank 2026: 10 Ranked, £99.99 Buys 20 or 54 Litres.
Questions people ask
How much water does the Fluval Flex 2.0 Black Aquarium Kit hold?
The specification table on the Fluval listing gives a Tank Volume of 57 litres, with item dimensions of 41.5 x 40 x 39 cm.
What is included with the Fluval Flex 2.0?
The listing's Included Components field names a circulation pump, glass aquarium, LED light, power supply and spray bar.
How much does the Fluval Flex 2.0 cost?
£129.99, which is £30 more than the £99.99 listings elsewhere in this guide.
What rating does the Fluval Flex 2.0 have?
4.6 out of 5 from 55 ratings as stated on the listing, with a Best Sellers Rank of 5 in Aquariums within Pet Supplies.
Is the Fluval Flex 2.0 for indoor use?
The listing's Specific Uses For Product field says Indoor and its Vivarium Type says Aquarium, while the same table puts Weather Resistant under Special Features — that is what the ad says, not something we measured.
How heavy is the Fluval Flex 2.0?
The listing gives 13.2 kg, a figure that fits a 57-litre glass tank, unlike the 200 g and 136 g weights given for other tanks in this guide.
Comments
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