2.5 Gallon

2.5 Gallon is a 30.5 × 15.2 × 20.3 cm (12 × 6 × 8 in) aquarium, rated at 9 L (2.5 gal). Its footprint is 30.5 × 15.2 cm and the water stands about 14.3 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.

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At a glance

Size30.5 × 15.2 × 20.3 cm (12 × 6 × 8 in)
Volume9 L (2.5 gal), as sold
Water after substrateAbout 6 L (2 gal) with a 6 cm substrate layer
Footprint30.5 × 15.2 cm (12 × 6 in)
Water depth14.3 cm (5.6 in)
Substrate neededAbout 3 L for a 6 cm layer

Before it goes in

  • 2.5 Gallon is 30.5 × 15.2 × 20.3 cm (12 × 6 × 8 in) — rated at 9 L (2.5 gal), and roughly 6 L (2 gal) of actual water once a 6 cm substrate layer and the hardscape are in.
  • That layer takes about 3 L of substrate, which is what you order by.
  • 3 of the 160 animals in this library list a minimum tank at or under 9 L (2.5 gal). The biggest of them that still fit are Malaysian Trumpet Snail and Ramshorn Snail. Nerite Snail and Assassin Snail need more than this.
  • The water sits about 14.3 cm (5.6 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 30.5 × 15.2 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?

30.5 × 15.2 × 20.3 cm (12 × 6 × 8 in).

How much water does it hold?

It is sold as 9 L (2.5 gal), and roughly 6 L (2 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 3 L for a 6 cm layer.

What fits in it?

3 of the 160 animals in this library list a minimum tank at or under its volume, and the water depth of about 14.3 cm sets which plants can grow without reaching the surface.

What fits in it

Often compared with

2.5 Gallon20C Cube30F Shallow
Size30.5 × 15.2 × 20.3 cm20 × 20 × 20 cm30 × 18 × 12 cm
Volume9 L8 L6 L
Footprint30.5 × 15.2 cm20 × 20 cm30 × 18 cm
Water depth14.3 cm14 cm6 cm

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