Finding a healthy fish for your saltwater aquarium can certainly make or break your success with a new tank. When it comes to choosing fish, there will always be a risk of getting a fish that is not in the healthiest of conditions and you want to do everything in your power to help maximize your success rates. It all starts at finding the right local fish store (LFS) but also observing the fish closely and following proper protocol will all play a role in the process of choosing the right fishy companion.

Let us help you beat the learning curve by following these 8 simple rules or guidelines when shopping for new fish at your local fish stores.  If you can manage everything on this list, you will have increased your chances of success tenfold, learn about the animals in your care, and maybe even find an aquarium mentor. 

1. Observe The Store & Staff

The general appearance of a fish store can really tell you quite a bit. Are the tanks clean? Are the employees attentive? A clean and organized store means they care about the animals in their care and, therefore, are invested in your success. This is the first positive sign of a reputable and responsible pet store, the store will be clean and the staff will be professional, friendly, and ready to help.

Don't shop at a store where something just doesn't feel right, it's just not worth it because more often than not, you and your tank questions are not the only things being neglected.

2. Observe The Tanks

Similar to #1, the very same rules apply to the tanks. Are they clean and algae-free? Do the fish have plenty of decor for hiding? Are there dead fish in the tanks? These things matter and are a direct reflection of the store and how they care for the animals.

Pay close attention to the filtration system and how it is set up. Ask the employees if you have to, they should be willing to share. If the tanks share a filtration system, that means they are sharing water.  In that scenario, you have to assume all the tanks connected to that particular filtration system could share diseases and parasites. So if you see a problem in one tank, but an otherwise healthy-looking fish in another shared tank, its still not a smart move to purchase that fish. Tanks that are filtered individually can be isolated and treated without affecting other holding tanks in the fish store.  

3. Ask About Quarantine Procedures

A store clerk should be open and honest about any QT - quarantine procedures. A good quarantine protocol will sound something like this.

"All new fish are isolated for 30-90 days in a separate system. If problems are observed, those fish are treated and not available for sale until they are observed healthy and disease-free for 30-90 days."

Should you find a fish store with a QT process like this, you have likely found the diamond in the rough and will increase your chances of finding a healthy fish with every visit. That being said, QT is expensive and time-consuming which means not all fish stores will do it and when they do, it is reflected in the cost of the animals. A healthy QT fish should and will cost more than a fish that has not been properly isolated before the sale. 

Not to say a fish store that doesn't QT isn't worth your efforts because there are plenty of fish stores that don't have a strict QT process but are still great resources.  After all, you can quarantine fish yourself at home which is technically the best advice regardless of where you purchased the fish.  

4. Observe Fish Behavior

When you find a healthy-looking fish from a reputable fish store, take some extra time to look for any signs of problems via the fish's behavior. Some of this is learned and not always obvious, there are exceptions to these rules too, but for the most part, here are the critical behaviors you want to watch out for.

  • Swim pattern - a healthy fish should not have trouble swimming or staying upright in a horizontal position
  • Breathing - heavy or fast breathing is a sign of illness. (compare to other members of the same species)
  • Sitting on the bottom or floating to the top is not normal for 99% of aquarium fish. (Stay in school!)
  • Gasping for air at the surface is typically not normal behavior outside of Betta Fish, Goldfish, and Koi
  • Fins should stay erect and function normally. Shredded or tattered fins are a sign of stress or illness.
  • Flashing is when fish dart or swim quickly and brush up against rocks, decor, or the aquarium walls. This is like "scratching and itch" and is a sign of external parasites
  • Fish should not appear to be afraid or constantly hiding unless that is normal for the species.  Some fish are simply solitary or like the burrow. 

5. Look For Injury Or Disease

In addition to observing a fish's behavior, look for signs of disease.  Bringing fish home with some kind of disease or parasite can put your entire aquarium at risk and will greatly decrease that particular fish's chances of survival. 

  • Red patches
  • White Dots
  • Open wounds
  • Torn fins
  • Fungus like growths
  • Bumps on the skin
  • Swollen belly
  • Concave or sunken belly
  • Stringy poop or worms from the anal vent
  • An obvious external parasitic creature
  • Red gills

6. Ask To Feed The Fish

You should ask the store clerk to feed the fish before you buy it. Most aquarium fish need to readily accept prepared aquarium foods (flakes and/or pellets).  Frozen foods are a tasty treat most any fish will eat, but accepting flakes and pellets is what will keep them healthy and alive in your home aquarium.   

Some fish are finicky eaters and some fish have specialized diets, this is true.  So its just as important for you to research the particular fish's diet to ensure you can provide for it.  Nonetheless, if the fish doesn't readily accept food you should probably pass.

7. Purchase & Hold

This step is not mandatory but if your fish store will do it, it is good practice.  Buy the fish, meaning physically pay for it, then ask the fish store to hold the animal for 1-2 weeks if you are unsure about the health of the fish.  This is especially good practice for more expensive or rare fish but really can help avoid bringing problems into any aquarium.  You're going to have to quarantine all new fish for 3-4 weeks at home and this initial process can help eliminate redundant efforts on your part should the fish not survive those initial 1-2 weeks.  

Fish only thrive in an aquarium once they have been acclimated which takes time.  In a fish store, you have no idea how long that fish has been in an aquarium and really no way to know for sure the fish's personal history. You are relying on the store to be honest with you 90% of the time.  If the store is willing to hold the fish, they are not only confident in their abilities and health of the fish, they are also invested in your success.  

8. Two Considerations

Always buy captive-bred fish when possible. 

They have a much higher rate of survival in aquariums, are less aggressive, have less likelihood of being sick, and are almost always ethically sourced. 

If you buy your fish online, you have no control over any of this.

There are some major advantages to buying fish at a local fish store. None of this works if you choose to purchase fish online.  If you do choose the buy online, there really are a ton of great sources you just have to do the legwork.  Look at customer reviews and get feedback from other hobbyists.

If the online company is honest and open about a strict quarantine protocol, even better.  This means they will likely charge more but the fish you get will, hypothetically, be healthy, acclimated to aquarium life, and ready for introduction into your tank. Essentially a "pre-quarantined" fish will always greatly increase your chances of success.