How to Add Saltwater Fish to Your Reef Tank

Adding new fish to your reef tank is exciting! But you need to do it the right way to keep your fish happy and healthy. Follow these steps to safely add saltwater fish to your tank.

Step 1: Pick the Right Fish

Not all fish are good for a reef tank. Some fish may eat your corals or fight with other fish. Before buying a fish, make sure it is reef-safe and will get along with your other fish.

Step 2: Quarantine Your Fish

A new fish can carry diseases that might spread to your tank. It’s best to keep the new fish in a separate quarantine tank for about two weeks. Watch for signs of sickness like spots, trouble swimming, or not eating. If the fish looks healthy after two weeks, it is safe to add to your reef tank.

Step 3: Acclimate Your Fish

Fish need time to get used to the water in your tank. There are two ways to do this:

• Float the Bag – Place the fish (still in its bag) in your tank for 15-20 minutes. This lets the water temperature match.
• Drip Acclimation – Slowly add small amounts of your tank’s water to the fish’s bag over 30-60 minutes. This helps the fish adjust to the water conditions.

Step 4: Turn Off the Lights

When you put your fish in the tank, turn off the lights for a few hours. This helps reduce stress and keeps other fish from bothering the new fish.

Step 5: Watch for Aggression

Some fish may try to chase or nip at the new fish. If this happens, try these steps to reduce saltwater fish aggression:

Last Resort – Rehome Aggressive Fish – If a fish continues to attack others, you may need to move it to another tank or find it a new home.

Rearrange the Rocks – Changing the layout of your tank can break up old territories and make fish less territorial.

Use a Breeding Box or Divider – If aggression is strong, temporarily place the new fish in a clear container inside the tank so other fish can get used to seeing it.

Feed More Often – Sometimes aggression happens when fish compete for food. Offering small meals throughout the day can help.

Add More Hiding Spots – Caves, PVC pipes, or extra rockwork give the new fish a place to hide until it feels safe.

Use a Mirror Trick – Placing a small mirror on the tank wall can distract aggressive fish by making them focus on their reflection.

Step 6: Feed Your Fish Well

A well-fed fish is a happy fish! Make sure your new fish eats and is not getting bullied by other fish. Offer a mix of pellets, frozen food, and live food if needed.

Step 7: Keep an Eye on Water Quality

Adding a new fish increases waste in your tank. Test your water for ammonia, nitrite, and nitrate to make sure your tank stays clean and safe.

Enjoy Your New Fish!

Adding a new fish to your reef tank is fun, but it takes time and care. Follow these steps, and your fish will have a happy, healthy home in your reef tank!