Purchasing a new saltwater fish is one of the most exciting parts of owning a marine aquarium. Saltwater fish are incredibly diverse, coming in myriad colors, shapes, and temperaments, meaning there is something for everyone. If you want a bright fuchsia and yellow fish, like a Bartlett’s Anthias or a Royal Gramma, or an invertebrate with a supersonic cannon for an arm, like a pistol shrimp, you can have one! There is something for everyone. Researching and selecting a new fish can be a fun and educational family activity, which involves the whole household in the hobby.
Although choosing a new fish is an exciting time, there are also potential dangers you want to avoid. That beautiful butterfly fish you have your eye on might have an eye to eat all your beautiful coral. That chocolate star might treat your coral like a box of chocolates. The tiny tang you see at the store will grow and need space to ♫ just keep swimming ♫. That psychedelic mandarin goby may starve when you can’t feed the right food. The clownfish may introduce a disease that wipes out your entire tank. So, before you select your new fish you need to do some studying, and then take steps to safely introduce your fish to its new home.
Here are the seven golden rules of buying fish
Perhaps you’re more of a Ron Weasley than a Hermione Granger, and never enjoyed studying. However, a little advanced research will really make a difference. Before adding a new fish, curate a stocking list of compatible species. Make a list of fish and invertebrates you want, then read up on the species to make sure you can meet its needs. Check our compatibility chart to ensure everything on your list can cohabitate. Here is where you can involve the whole family, learning together as you enjoy the aquarium hobby. Once you’re ready, take your stocking list to the local fish store (LFS).
Ask plenty of questions at the LFS. How long has the fish been in the store? Is it captive bred or wild caught? Is it reef safe? How big will it get? How much space does it need? What does it eat? Is it compatible with the other species on your list? What temperature and salinity is the water? These questions will help you determine if the fish or invert is a good fit for you and how you should acclimate it.
Do keep in mind, while most LFS employees are passionate about the hobby and want to help you succeed, a few might be more interested in making a quick sale. If the LFS tells you something that contradicts your research, consider holding off on the purchase until you can be sure. Ask the LFS to hold the fish and double-check your information.
Tell the LFS worker about your tank. Let them know how long it has been running, how big it is, about the water quality, and whether it contains invertebrates. Tell them what fish you already have, what you plan to keep, and if any fish have recently died.
Watch the fish swim around. Is it breathing normally? Does it have clear eyes? Are its fins intact? Can the fish maintain a steady position in the water? Are there any unusual spots or growths on its skin? Is it getting bullied? Does it look settled and calm?
Ask the assistant to add some food so you can watch the fish feed. If it does not feed quickly and well, either choose not to purchase it or have the LFS hold the fish until it is feeding well. It may be sick or not fully acclimated to aquarium life.
Tell the lfs how long the fish will be in the bag. If it will be several hours, request a styrofoam box and a warming pack. Secure the box in the car and take the fish home as quickly and as safely as possible.
You can shock and kill a fish by just dumping it into the tank from a bag. Acclimate the fish to the new tank’s temperature and salinity slowly using the drip method. Cover the top of the opened bag, box or bucket as new fish may jump. If possible, do so under low light to help calm the fish. If possible, transfer the fish into your display tank at night, when other fish are calm and the new fish has the opportunity to hide as it adjusts to its new home.
If you want to succeed and keep your tank inhabitants safe long term, you will use a quarantine system. A quarantine tank is a small, basic aquarium which you will use to observe (and possibly treat) a new fish before it goes into your main display tank. Some issues, like certain diseases and parasites, may not show up for days. We recommend a two week quarantine period. Place all newly purchased fish into a quarantine tank and observe them over the next few weeks. Only introduce them to the main display tank when they are feeding, settled and 100% disease-free.