55 Gallon

55 Gallon is a 121.9 × 33 × 53.3 cm (48 × 13 × 21 in) aquarium, rated at 208 L (55 gal). Its footprint is 121.9 × 33 cm and the water stands about 47.3 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

Size121.9 × 33 × 53.3 cm (48 × 13 × 21 in)
Volume208 L (55 gal), as sold
Water after substrateAbout 175 L (46 gal) with a 6 cm substrate layer
Footprint121.9 × 33 cm (48 × 13 in)
Water depth47.3 cm (18.6 in)
Substrate neededAbout 24 L for a 6 cm layer

Before it goes in

  • 55 Gallon is 121.9 × 33 × 53.3 cm (48 × 13 × 21 in) — rated at 208 L (55 gal), and roughly 175 L (46 gal) of actual water once a 6 cm substrate layer and the hardscape are in.
  • That layer takes about 24 L of substrate, which is what you order by.
  • 138 of the 160 animals in this library list a minimum tank at or under 208 L (55 gal). The biggest of them that still fit are Boesemani Rainbowfish and Siamese Algae Eater. Denison Barb and Dojo Loach need more than this.
  • The water sits about 47.3 cm (18.6 in) deep over the substrate. Plants that get taller than that — Hygrophila corymbosa 'Siamensis' and Amazon Sword — reach the surface and start growing along it, which is a look you either want or trim.
  • Its footprint is 121.9 × 33 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?

121.9 × 33 × 53.3 cm (48 × 13 × 21 in).

How much water does it hold?

It is sold as 208 L (55 gal), and roughly 175 L (46 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 24 L for a 6 cm layer.

What fits in it?

138 of the 160 animals in this library list a minimum tank at or under its volume, and the water depth of about 47.3 cm sets which plants can grow without reaching the surface.

What fits in it

Often compared with

55 Gallon90PJuwel Rio 180
Size121.9 × 33 × 53.3 cm90 × 45 × 45 cm101 × 41 × 50 cm
Volume208 L182 L180 L
Footprint121.9 × 33 cm90 × 45 cm101 × 41 cm
Water depth47.3 cm39 cm44 cm

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