Fluval Flex 15
Fluval Flex 15 is a 41 × 39 × 39 cm (16.1 × 15.4 × 15.4 in) aquarium, rated at 57 L (15 gal). Its footprint is 41 × 39 cm and the water stands about 33 cm deep once a 6 cm substrate layer is in — the two numbers that decide what you can plant in it and what you can stock it with.
At a glance
| Size | 41 × 39 × 39 cm (16.1 × 15.4 × 15.4 in) |
|---|---|
| Volume | 57 L (15 gal), as sold |
| Water after substrate | About 49 L (13 gal) with a 6 cm substrate layer |
| Footprint | 41 × 39 cm (16.1 × 15.4 in) |
| Water depth | 33 cm (13 in) |
| Substrate needed | About 10 L for a 6 cm layer |
Before it goes in
- Fluval Flex 15 is 41 × 39 × 39 cm (16.1 × 15.4 × 15.4 in) — rated at 57 L (15 gal), and roughly 49 L (13 gal) of actual water once a 6 cm substrate layer and the hardscape are in.
- That layer takes about 10 L of substrate, which is what you order by.
- 68 of the 160 animals in this library list a minimum tank at or under 57 L (15 gal). The biggest of them that still fit are Chinese Fire-bellied Newt and Borneo Sucker Loach. Apistogramma agassizii and Apistogramma cacatuoides need more than this.
- The water sits about 33 cm (13 in) deep over the substrate. Plants that get taller than that — Hygrophila corymbosa 'Siamensis' and Water Sprite — reach the surface and start growing along it, which is a look you either want or trim.
- Its footprint is 41 × 39 cm, and that is the area a carpet has to cover — the number that decides how many pots you buy, not the volume.
What are its dimensions?
41 × 39 × 39 cm (16.1 × 15.4 × 15.4 in).
How much water does it hold?
It is sold as 57 L (15 gal), and roughly 49 L (13 gal) of actual water once the substrate is in. Stocking works off the second number; minimum-tank-size advice works off the first.
How much substrate does it take?
About 10 L for a 6 cm layer.
What fits in it?
68 of the 160 animals in this library list a minimum tank at or under its volume, and the water depth of about 33 cm sets which plants can grow without reaching the surface.
What fits in it
- Animals this size will hold: Chinese Fire-bellied Newt, Salt and Pepper Cory, Kubotai Rasbora, Borneo Sucker Loach and Butterfly Hillstream Loach.
- Plants that stay under its water line: Anubias nana 'Petite', Cryptocoryne wendtii, Dwarf Hairgrass Mini and Frogbit.
Often compared with
| Fluval Flex 15 | 15 Gallon | Dennerle Nano Cube 60L | |
|---|---|---|---|
| Size | 41 × 39 × 39 cm | 61 × 30.5 × 30.5 cm | 38 × 38 × 43 cm |
| Volume | 57 L | 57 L | 60 L |
| Footprint | 41 × 39 cm | 61 × 30.5 cm | 38 × 38 cm |
| Water depth | 33 cm | 24.5 cm | 37 cm |