Adding water to a saltwater tank is crucial for maintaining stable salinity and water levels. The best method depends on whether you're topping off due to evaporation or performing a water change.
Topping Off Your Saltwater Tank
For daily evaporation, the simplest and most effective method is to regularly top off with fresh, clean water. This maintains salinity without the need for large, disruptive water changes.
- Use RO/DI (Reverse Osmosis/Deionized) water: This removes impurities that can harm your tank's inhabitants and negatively impact water quality. Avoid using tap water as it contains minerals and chemicals harmful to marine life.
- Keep a ready supply: A 5-gallon bucket of RO/DI water stored near your tank allows for quick and convenient topping off during daily feeding, typically taking only about 30 seconds (Bulk Reef Supply, 2021). This consistent approach ensures stable salinity.
- Gentle addition: Slowly add the water to avoid sudden changes in water level or temperature. Avoid directly pouring it onto corals or other sensitive inhabitants.
Performing a Water Change in Your Saltwater Tank
Larger water changes are necessary for maintaining overall water quality. This involves removing a portion of the existing saltwater and replacing it with freshly mixed saltwater.
- Prepare new saltwater: Mix saltwater according to the instructions on your salt mix packaging. Ensure the temperature of the new saltwater closely matches that of the tank water. (Many resources offer step-by-step guidance for preparing saltwater. See, for example, videos on YouTube showing how to mix saltwater.)
- Gradual Replacement: Remove old saltwater using a siphon or other appropriate method, then gradually add the fresh saltwater.
- Consider Water Temperature: Pre-heating your water to match your tank's temperature is generally recommended to minimize stress on marine life (Reef2Reef, 2019).
While adding salt directly to existing tank water is technically possible, it’s best to mix the salt and water separately first for even distribution (Reef2Reef, 2019).
