20 Gallon Long tank dimensions
30×12×12inches
Length × width × height. In metric, 76.2 × 30.5 × 30.5 cm.
A standard 20 gallon long aquarium is 30 inches long, 12 inches front to back and 12 inches tall. By the numbers it holds 18.7 gallons to the brim, which is less than the name says. Once you add gravel and leave a gap at the top, expect a little less water than that.
How much a 20 gallon long tank weighs
Empty, the glass tank weighs about 23 pounds. Filled with water and two inches of gravel it comes to roughly 229 pounds, before rocks, wood or equipment.
A weight like this is fine on any sound floor, but it needs a stand built for aquariums: ordinary furniture is not made for a load that never moves.
| Empty tank | about 23 lb |
|---|---|
| Water (20 gallons) | 167 lb |
| Gravel, 2 inches deep | about 39 lb |
| Filled, with gravel | about 229 lb |
| Load on the floor | about 92 lb per sq ft |
Stand, lid, heater and filter sizes
The stand and the lid both follow the footprint, 30 by 12 inches. A stand has to support the whole bottom frame, so it can be bigger than the tank but never smaller.
The 20 gallon long has the same 30 x 12 inch footprint as the 29 gallon, 37 gallon, so they share stands and lids.
For a heated tropical tank, a 100 W heater suits a normal room. Pick a filter rated to turn the water over four to six times an hour.
| Footprint | 30 x 12 in (2.5 sq ft) |
|---|---|
| Volume | 20 gal (75.7 L) |
| Heater | 100 W |
| Filter flow | 80 to 120 gal per hour |
| Typical glass | about 3/16 in thick |
What fish can live in a 20 gallon long 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 21
- Ember tetraup to 31
- Guppyup to 10
- Harlequin rasboraup to 14
- Zebra danioup to 12 *
- Cherry barbup to 12
- Platyup to 12
- Panda coryup to 12
- Bronze coryup to 8
- Honey gouramiup to 6
- Dwarf gourami1 only
- Pearl gouramiup to 3 *
- Tiger barbup to 10
- Mollyup to 7 *
- Bristlenose pleco1 only
- German blue ramup to 2
- Electric yellow labup to 4 *
* Fits by volume, but the footprint is under what Seriously Fish recommends for the species.
Plan a 20 gallon long community How many fish in a 20 gallon tank?
Too big for this tank
- Angelfish needs a bigger tank: the recommended minimum is a 39 x 16 in footprint.
- Fancy goldfish needs a bigger tank: the recommended minimum is 26 gallons.
- Boeseman's rainbowfish needs a bigger tank: the recommended minimum is a 47 x 12 in footprint.
- Discus needs a bigger tank: the recommended minimum is a 47 x 18 in footprint.
- Clown loach needs a bigger tank: the recommended minimum is a 71 x 24 in footprint.
- Oscar needs a bigger tank: the recommended minimum is a 59 x 24 in footprint.
Gear for a 20 gallon long 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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