Here's why:
* Cycling the tank: The most important reason is to allow the tank to cycle. Cycling refers to establishing a healthy bacterial colony that breaks down ammonia and nitrite, which are toxic to fish. This process takes about 2 weeks.
* Stability: The tank needs time to stabilize its water parameters (temperature, salinity, pH, etc.) before introducing fish.
* Acclimation: Introducing fish too early can shock them and make them more susceptible to disease.
Here's a general timeline for setting up a saltwater tank:
1. Set up the tank: Install the filter, heater, and other equipment.
2. Add saltwater: Use a pre-mixed saltwater solution or mix your own using the correct salt mix and specific gravity.
3. Add live rock: Live rock is a vital part of a saltwater ecosystem.
4. Monitor parameters: Check your tank's temperature, salinity, pH, ammonia, nitrite, and nitrate levels daily.
5. Wait for cycling: After about 2 weeks, the tank should be cycled and ready for fish.
Important note: Always research the specific needs of the fish you want to keep. Some species may require larger tanks or different conditions than others.
Remember, setting up a saltwater tank is a commitment. Taking your time and ensuring the tank is properly cycled will give your fish the best chance at a healthy and happy life.