125 Gallon

125 Gallon is a 182.9 × 45.7 × 55.9 cm (72 × 18 × 22 in) aquarium, rated at 473 L (125 gal). Its footprint is 182.9 × 45.7 cm and the water stands about 49.9 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.

Start a tank this size

At a glance

Size182.9 × 45.7 × 55.9 cm (72 × 18 × 22 in)
Volume473 L (125 gal), as sold
Water after substrateAbout 384 L (101 gal) with a 6 cm substrate layer
Footprint182.9 × 45.7 cm (72 × 18 in)
Water depth49.9 cm (19.6 in)
Substrate neededAbout 50 L for a 6 cm layer

Before it goes in

  • 125 Gallon is 182.9 × 45.7 × 55.9 cm (72 × 18 × 22 in) — rated at 473 L (125 gal), and roughly 384 L (101 gal) of actual water once a 6 cm substrate layer and the hardscape are in.
  • That layer takes about 50 L of substrate, which is what you order by.
  • 154 of the 160 animals in this library list a minimum tank at or under 473 L (125 gal). The biggest of them that still fit are Black Ghost Knifefish and Common Pleco. Oscar and Senegal Bichir need more than this.
  • The water sits about 49.9 cm (19.6 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 182.9 × 45.7 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?

182.9 × 45.7 × 55.9 cm (72 × 18 × 22 in).

How much water does it hold?

It is sold as 473 L (125 gal), and roughly 384 L (101 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 50 L for a 6 cm layer.

What fits in it?

154 of the 160 animals in this library list a minimum tank at or under its volume, and the water depth of about 49.9 cm sets which plants can grow without reaching the surface.

What fits in it

Often compared with

125 Gallon90 Gallon180P
Size182.9 × 45.7 × 55.9 cm121.9 × 45.7 × 61 cm180 × 60 × 60 cm
Volume473 L341 L648 L
Footprint182.9 × 45.7 cm121.9 × 45.7 cm180 × 60 cm
Water depth49.9 cm55 cm54 cm

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