A comparison table, not a buying guide
The table converts nominal litre figures into both gallon systems and shows the rough freshwater mass of the water alone. It does not claim that a model sold under one of these numbers contains exactly that much water after setup.
| Nominal litres | UK gallons | US gallons | Water mass (rough freshwater planning) |
|---|---|---|---|
| 20 L | 4.4 | 5.3 | ≈ 20 kg before tank/stand/substrate |
| 30 L | 6.6 | 7.9 | ≈ 30 kg before tank/stand/substrate |
| 40 L | 8.8 | 10.6 | ≈ 40 kg before tank/stand/substrate |
| 54 L | 11.9 | 14.3 | ≈ 54 kg before tank/stand/substrate |
| 60 L | 13.2 | 15.9 | ≈ 60 kg before tank/stand/substrate |
| 80 L | 17.6 | 21.1 | ≈ 80 kg before tank/stand/substrate |
| 100 L | 22.0 | 26.4 | ≈ 100 kg before tank/stand/substrate |
| 120 L | 26.4 | 31.7 | ≈ 120 kg before tank/stand/substrate |
| 150 L | 33.0 | 39.6 | ≈ 150 kg before tank/stand/substrate |
| 180 L | 39.6 | 47.6 | ≈ 180 kg before tank/stand/substrate |
| 200 L | 44.0 | 52.8 | ≈ 200 kg before tank/stand/substrate |
| 240 L | 52.8 | 63.4 | ≈ 240 kg before tank/stand/substrate |
| 300 L | 66.0 | 79.3 | ≈ 300 kg before tank/stand/substrate |
| 400 L | 88.0 | 105.7 | ≈ 400 kg before tank/stand/substrate |
| 500 L | 110.0 | 132.1 | ≈ 500 kg before tank/stand/substrate |