What is a 120×40×50 cm tank good for?
A 120×40×50 cm tank holds 240 liters, close to a 65 gallon tank in American sizes. At this length it suits active schooling fish and medium cichlids, and it needs a stand built for aquariums.
How much water does it really hold?
The label says 240 liters (63 US gallons). That is the tank filled to the very brim, measured from outside the glass. In real life the glass, the gap at the top, the gravel and the decor take up room. A set-up 120×40×50 cm tank holds about 204 liters (54 US gallons). Use that smaller number when you dose medicine or water conditioner. Work out your exact water volume
How much does a 120×40×50 cm tank weigh?
An empty glass 120×40×50 cm tank weighs about 40 kg (90 lb). Filled, with gravel and a few rocks, it weighs about 290 kg (645 lb). That is as much as a grand piano, so use a stand made for aquariums, not ordinary furniture. The load on the floor under the tank is about 610 kg/m² (125 lb per square foot). Add your own stand and rocks
What size heater does it need?
The colder your room, the bigger the heater. These sizes hold the water at 78 °F (25.5 °C), right for most tropical fish.
| Your room | Heater to buy |
|---|---|
| Warm room, 73 °F (23 °C) | 2 × 75 W |
| Normal room, 68 °F (20 °C) | 2 × 150 W |
| Cold room, 63 °F (17 °C) | 2 × 250 W |
Check your own room and target temperature
What size filter does it need?
For a community tank, look for a filter rated at 800–1,200 L/h (220–320 GPH). That moves all the water through the filter four to six times an hour. Goldfish and big cichlids need more. Size a filter for your kind of tank
How much gravel or sand?
| Depth | Gravel | Sand |
|---|---|---|
| 1 in (2.5 cm) | 18 kg40 lb | 20 kg43 lb |
| 2 in (5 cm) | 36 kg80 lb | 39 kg85 lb |
| 3 in (7.5 cm) | 54 kg120 lb | 58 kg127 lb |
Two inches suits most tanks. Rooted plants like three. Work it out in bags
How much water to change
A normal weekly water change is a quarter of the water: about 51 liters (13.5 US gallons) for this tank. A big clean-up change is half: about 102 liters (27 US gallons). Plan changes from your nitrate reading
How many fish can go in a 120×40×50 cm tank?
It depends on which fish. The table shows how many of each the tank carries comfortably if that fish is the only kind in the tank. If you mix kinds, keep fewer of each.
| Fish | How many | Keep at least |
|---|---|---|
| Neon tetra | up to 51 | 6 |
| Guppy | up to 29 | 3 |
| Bronze corydoras | up to 22 | 6 |
| Molly | up to 11 | 3 |
| Tiger barb | up to 20 | 8 |
| Pearl gourami | up to 4 | 1 |
| Bristlenose pleco | up to 4 | 1 |
| Yellow lab | up to 11 | 4 |
| Angelfish | up to 2 | 1 |
| Boeseman's rainbowfish | up to 9 | 6 |
Build your own fish list for this tank
Fish that need a bigger tank
These fish are often sold for tanks this size, but they outgrow it:
- Common goldfish: grows to 12 in (30 cm) and needs at least 284 liters (75 US gallons).
- Oscar: grows to 12 in (30 cm) and needs at least 284 liters (75 US gallons).
- Common pleco: grows to 16 in (40 cm) and needs at least 570 liters (150 US gallons).
- Bala shark: grows to 14 in (35 cm) and needs at least 570 liters (150 US gallons).
Questions and answers
How many liters is a 120×40×50 cm aquarium?
A 120×40×50 cm tank is 240 liters brim-full (63 US gallons, 53 UK gallons). Set up, it holds about 204 liters of water.
How much does a 120×40×50 cm tank weigh?
Empty, about 40 kg (90 lb). Filled with water, gravel and rocks, about 290 kg (645 lb). Add the weight of the stand to find the load on your floor.
What size heater does a 120×40×50 cm tank need?
In a normal room at 68 °F (20 °C), 2 × 150 W holds 78 °F (25.5 °C). In a cold room use 2 × 250 W; in a warm room 2 × 75 W is enough.
How many fish can I put in a 120×40×50 cm tank?
It depends on the fish, not just the gallons. As the only kind in the tank, a 120×40×50 cm tank carries about 51 neon tetras, or 29 guppies, or 22 bronze corydoras. Mixed tanks hold fewer of each.
Other tank sizes
Dimensions are the common North American and European standard sizes; brands differ slightly. Weights assume float glass of typical thickness, 4 cm of gravel and light rockwork. How we calculate