A saltwater sump should be at least 25% of the total water volume of your display tank.
Here's a more detailed breakdown to help you determine the ideal size:
Factors Influencing Sump Size
Two primary considerations dictate the size of your saltwater sump:
- Sufficient Capacity: The sump needs to hold enough water to handle overflows from the display tank when the pump is turned off (power outage) and provide adequate space for equipment.
- Available Space: The physical space you have available to house the sump is a practical limitation.
Calculating Minimum Sump Size
As stated previously, a good rule of thumb is to aim for a sump that holds at least 25% of your display tank's water volume.
| Display Tank Size (Gallons) | Minimum Sump Size (Gallons) |
|---|---|
| 50 | 12.5 |
| 75 | 18.75 |
| 100 | 25 |
| 125 | 31.25 |
| 150 | 37.5 |
Why is sump size important?
- Prevents Overflow: When the return pump is off, water from the display tank drains down into the sump. A properly sized sump will have enough capacity to accommodate this without overflowing.
- Provides Room for Equipment: Sumps house essential equipment like protein skimmers, reactors, heaters, and refugiums. Ensure enough space for the equipment you plan to use.
- Water Volume Stability: A larger sump adds to the overall water volume of your system, leading to greater stability in water parameters like temperature, pH, and salinity.
Considerations Beyond the Minimum
While 25% is a good minimum, consider going larger if you have the space. A larger sump provides more buffer capacity and allows for future upgrades. Some hobbyists even opt for sumps that are closer to 50% or more of their display tank's volume.
