So your tank is cycled and ready for fish, but my gosh the options are endless and it feels like you want all of them.  

This is something that most new aquarists will encounter and it's important to stay focused when it comes to choosing fish.  Not all fish are compatible with each other and you must bear in mind the limitations of your tank in terms of size. In general, small reef fish can live in small aquariums, and fish that grow large need large aquariums. 

It is also best to add no more than 1-2 fish at a time. Spread out the addition of fish every two weeks or more so as not to overload the aquarium with an increased level of nutrients. Observe new fish closely to ensure they are eating and generally displaying normal behavior.  

Captive-Bred Fish

With first-time tank owners, stick to hardy fish that are generally peaceful. One of the smartest routes is to source captive-bred saltwater fish which are already adapted to life inside an aquarium. Compared to wild-caught fish, they are hardier, easier to feed, less aggressive, and sustainable!  Thanks to modern aquaculture techniques, there is an incredible variety of captive-bred ornamental fish available, you just need to look for them. Ask your local fish store or research online to see what's available. With such widespread success, breeders are adding new species each and every year. As of 2019, there were over 400 unique species of saltwater fish bred in captivity and by now that number is probably closer to 500. 

 Acclimating New Fish

Upon bringing fish home, it's important to give them a gentle introduction to your aquarium.  If the fish are shipped inside a box, open the box slowly so as not to shock the fish with sudden exposure to bright light. It's best to turn out the lights both over the aquarium and in the surrounding room while acclimating fish.

  1. Grab a bucket, scissors, and a cup
  2. Float the fish in the bags in your aquarium for about 30 minutes to equalize the water temperature. 
  3. Cut open the bags and pour them into the bucket one by one. Do not allow water from the bags to get into your aquarium. 
  4. Add a cup of aquarium water to the bucket every 5 minutes.  When you have doubled the water volume in the bucket, you can empty half the water and repeat.  The process shouldn't last more than 30 minutes give or take. 
  5. Scoop each fish using a net or your hands and add them to the aquarium. 
  6. Do not feed new fish right away, the usually won't eat until 2nd or 3rd day in the aquarium as they need time to settle. 

Example Livestock List

Invertebrate Clean-Up Crew

  • Variegated Sea Urchins
  • Peppermint Shrimp
  • Conchs
  • banded Trochus Snails
  • Scarlet Reef Hermit Crabs
  • Cerith Snail


  • Clownfish
  • Watchman goby with Pistol Shrimp
  • Pygmy Filefish
  • Neon Dottyback (with caution)
  • Small Blenny
  • Neon Goby


With the addition of fish, you're going to see an increase in nutrient levels which means its time to start performing weekly water changes.  The process requires you mix up clean saltwater and remove at least 10% of the aquarium's total water volume and replace it with clean saltwater. This will help maintain stability in the aquarium. 

During this weekly maintenance, you should clean your filtration and replace any filter media as needed.  

You may see an increase in algae growth and those clean-up crew critters will be valuable in this regard. Use a magnetic algae cleaner to keep the glass walls clean on a daily basis. Its better to do this daily which will prevent the algae from building up thick which makes it more difficult to remove.