125 Gallon tank dimensions
72×18×22inches
Length × width × height. In metric, 182.9 × 45.7 × 55.9 cm.
A standard 125 gallon aquarium is 72 inches long, 18 inches front to back and 22 inches tall. Its measurements work out to almost exactly the volume on the label. Once you add gravel and leave a gap at the top, expect a little less water than that.
How much a 125 gallon tank weighs
Empty, the glass tank weighs about 178 pounds. Filled with water and two inches of gravel it comes to roughly 1,360 pounds, before rocks, wood or equipment.
That is the weight of several people standing in one spot for years. Put it on a purpose-built stand, across the floor joists or near a load-bearing wall, and check an upstairs floor before you fill it.
| Empty tank | about 178 lb |
|---|---|
| Water (125 gallons) | 1,042 lb |
| Gravel, 2 inches deep | about 140 lb |
| Filled, with gravel | about 1,360 lb |
| Load on the floor | about 151 lb per sq ft |
Stand, lid, heater and filter sizes
The stand and the lid both follow the footprint, 72 by 18 inches. A stand has to support the whole bottom frame, so it can be bigger than the tank but never smaller.
The 125 gallon has the same 72 x 18 inch footprint as the 150 gallon, so they share stands and lids.
For a heated tropical tank, a 2 x 250 W heater suits a normal room. Two heaters split the load and fail safer. Pick a filter rated to turn the water over four to six times an hour.
| Footprint | 72 x 18 in (9 sq ft) |
|---|---|
| Volume | 125 gal (473.2 L) |
| Heater | 2 x 250 W |
| Filter flow | 500 to 750 gal per hour |
| Typical glass | about 3/8 in thick |
What fish can live in a 125 gallon tank
How many of each fish would fill this tank on its own. Mix species and the numbers come down, so plan a real community with the calculator.
- Betta1 only
- Neon tetraup to 139
- Ember tetraup to 209
- Guppyup to 69
- Harlequin rasboraup to 92
- Zebra danioup to 83
- Cherry barbup to 83
- Platyup to 83
- Panda coryup to 83
- Bronze coryup to 55
- Honey gouramiup to 6
- Dwarf gourami1 only
- Pearl gouramiup to 4
- Tiger barbup to 69
- Mollyup to 50
- Angelfishup to 6
- Fancy goldfishup to 6
- Bristlenose pleco1 only
- Boeseman's rainbowfishup to 28
- German blue ramup to 2
- Electric yellow labup to 28
- Discusup to 12
- Oscar1 only *
- Common goldfish1 only
* Fits by volume, but the footprint is under what Seriously Fish recommends for the species.
Too big for this tank
- Clown loach needs a group of 5 or more, and this tank only has room for 3.
- Common pleco grows too big for this tank.
- Bala shark needs a bigger tank: the recommended minimum is a 94 x 24 in footprint.
Gear for a 125 gallon tank
Searches on Amazon for the right size. Check the tank size or flow rating on the listing before you buy.
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