What is a 80×35×40 cm tank good for?
A 80×35×40 cm tank holds 112 liters, close to a 30 gallon breeder tank in American sizes. It is a popular first community tank: big enough to stay stable, small enough for most rooms.
How much water does it really hold?
The label says 112 liters (30 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 80×35×40 cm tank holds about 95 liters (25 US gallons). Use that smaller number when you dose medicine or water conditioner. Work out your exact water volume
How much does a 80×35×40 cm tank weigh?
An empty glass 80×35×40 cm tank weighs about 15 kg (35 lb). Filled, with gravel and a few rocks, it weighs about 135 kg (300 lb). That is as much as two or three adults, so use a stand made for aquariums, not ordinary furniture. The load on the floor under the tank is about 480 kg/m² (99 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) | 75 W |
| Normal room, 68 °F (20 °C) | 150 W |
| Cold room, 63 °F (17 °C) | 200 W |
Check your own room and target temperature
What size filter does it need?
For a community tank, look for a filter rated at 400–550 L/h (100–150 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) | 11 kg24 lb | 12 kg25 lb |
| 2 in (5 cm) | 21 kg47 lb | 23 kg50 lb |
| 3 in (7.5 cm) | 32 kg70 lb | 34 kg75 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 24 liters (6.3 US gallons) for this tank. A big clean-up change is half: about 48 liters (12.6 US gallons). Plan changes from your nitrate reading
How many fish can go in a 80×35×40 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 24 | 6 |
| Guppy | up to 13 | 3 |
| Bronze corydoras | up to 10 | 6 |
| Zebra danio | up to 16 | 6 |
| Molly | up to 5 | 3 |
| Tiger barb | up to 9 | 8 |
| Pearl gourami | 1 | 1 |
| Bristlenose pleco | 1 | 1 |
| Dwarf neon rainbowfish | up to 11 | 6 |
| Fancy goldfish | 1 | 1 |
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 80×35×40 cm aquarium?
A 80×35×40 cm tank is 112 liters brim-full (30 US gallons, 25 UK gallons). Set up, it holds about 95 liters of water.
How much does a 80×35×40 cm tank weigh?
Empty, about 15 kg (35 lb). Filled with water, gravel and rocks, about 135 kg (300 lb). Add the weight of the stand to find the load on your floor.
What size heater does a 80×35×40 cm tank need?
In a normal room at 68 °F (20 °C), 150 W holds 78 °F (25.5 °C). In a cold room use 200 W; in a warm room 75 W is enough.
How many fish can I put in a 80×35×40 cm tank?
It depends on the fish, not just the gallons. As the only kind in the tank, a 80×35×40 cm tank carries about 24 neon tetras, or 13 guppies, or 10 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