What is a 15 gallon tank good for?
A 15 gallon gives you the two-foot length of a 20 gallon high in a lower, lighter tank. It suits one school of small fish plus a few bottom dwellers.
How much water does it really hold?
The label says 15 gallons (57 liters). 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 15 gallon tank holds about 12.8 gallons (48 liters). Use that smaller number when you dose medicine or water conditioner. Work out your exact water volume
How much does a 15 gallon tank weigh?
An empty glass 15 gallon tank weighs about 16 lb (7 kg). Filled, with gravel and a few rocks, it weighs about 155 lb (70 kg). That is as much as an adult person, so put it on a sturdy, level surface. The load on the floor under the tank is about 78 lb per square foot (380 kg/m²). 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) | 50 W |
| Normal room, 68 °F (20 °C) | 75 W |
| Cold room, 63 °F (17 °C) | 100 W |
Check your own room and target temperature
What size filter does it need?
For a community tank, look for a filter rated at 50–80 GPH (200–300 L/h). 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) | 16 lb7 kg | 17 lb8 kg |
| 2 in (5 cm) | 31 lb14 kg | 33 lb15 kg |
| 3 in (7.5 cm) | 47 lb21 kg | 50 lb23 kg |
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 3.2 gallons (12 liters) for this tank. A big clean-up change is half: about 6.4 gallons (24 liters). Plan changes from your nitrate reading
How many fish can go in a 15 gallon 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 |
|---|---|---|
| Betta | 1 | 1 |
| Chili rasbora | up to 21 | 8 |
| Neon tetra | up to 12 | 6 |
| Guppy | up to 6 | 3 |
| Ember tetra | up to 21 | 8 |
| Harlequin rasbora | up to 9 | 6 |
| Platy | up to 5 | 3 |
| Panda corydoras | up to 8 | 6 |
| Honey gourami | 1 | 1 |
| Dwarf gourami | 1 male | 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 75 gallons (284 liters).
- Oscar: grows to 12 in (30 cm) and needs at least 75 gallons (284 liters).
- Common pleco: grows to 16 in (40 cm) and needs at least 150 gallons (570 liters).
- Bala shark: grows to 14 in (35 cm) and needs at least 150 gallons (570 liters).
Questions and answers
What are the dimensions of a 15 gallon tank?
A standard 15 gallon glass tank is 24 × 12 × 12 inches (61 × 30 × 30 cm), measured on the outside as length × width × height. Brands differ by up to half an inch.
How much does a 15 gallon tank weigh?
Empty, about 16 lb (7 kg). Filled with water, gravel and rocks, about 155 lb (70 kg). Add the weight of the stand to find the load on your floor.
What size heater does a 15 gallon tank need?
In a normal room at 68 °F (20 °C), 75 W holds 78 °F (25.5 °C). In a cold room use 100 W; in a warm room 50 W is enough.
How many fish can I put in a 15 gallon tank?
It depends on the fish, not just the gallons. As the only kind in the tank, a 15 gallon tank carries about 1 betta, or 21 chili rasboras, or 12 neon tetras. Mixed tanks hold fewer of each.
How many liters is a 15 gallon tank?
15 US gallons is 57 liters. Once set up with gravel and decor, the tank holds about 48 liters (13 gallons) of water.
Other tank sizes
Dimensions are the common North American and European standard sizes; brands differ slightly. Weights assume standard glass of typical thickness, 4 cm of gravel and light rockwork. How we calculate