𝐓𝐨𝐩 𝟓 𝐐𝐮𝐞𝐬𝐭𝐢𝐨𝐧𝐬 𝐭𝐨 𝐀𝐬𝐤 𝐁𝐄𝐅𝐎𝐑𝐄 𝐁𝐮𝐲𝐢𝐧𝐠 𝐚 𝐅𝐢𝐬𝐡

Introduction

We’ve all been there—standing in front of a tank at the fish store, mesmerized by a beautiful fish, thinking, I need this in my life. Maybe it’s the perfect shade of blue, maybe it’s swimming with personality, or maybe you just really want to take something home today. But before you bag it up and swipe your card, take a step back!

Not all fish are as easy to care for as they seem, and impulse buys can lead to disaster for both your tank and your new finned friend. Asking the right questions before purchasing a fish can save you from headaches, compatibility issues, and unexpected tank crashes.

So before you bring home that new fish, here are five essential questions every aquarist should ask to make sure it’s the right fit for their tank. Trust me—your future self (and your current fish) will thank you!

1. What is it eating, and can I see it eat?

• • Always ask to see the fish eat before purchasing. If it refuses food, it could be stressed, sick, or a picky eater that won’t transition to prepared foods easily. Knowing its current diet helps you avoid a starvation situation at home.

Tamara'a Pro Tip: Whatever the fish is currently eating, make sure to purchase that exact food. You can always transition to the diet you typically feed, but it is important to make sure they are as comfortable eating in the beginning as possible.

2. Was it wild-caught or captive-bred?

• • Wild-caught fish may struggle to adapt to captivity, while captive-bred fish are generally hardier, more accustomed to aquarium life, and less likely to carry diseases or parasites. Some species are only available wild-caught, so you’ll need to research if special care is needed.

3. When did it arrive at the store?

• • Fish that just arrived may still be stressed from transport and not eating properly. A fish that has been at the store for at least a week with no signs of illness is a safer choice.

4. Has it had any issues with tank mates?

• • If the fish is coming from a tank with other livestock, ask if it has been aggressive, bullied, or acting strangely. Some fish become territorial in small spaces, and you don’t want to bring home a problem fish.

5. Has it been quarantined or treated for disease?

• • Find out if the store quarantines new arrivals or if they’ve noticed signs of parasites, infections, or other health concerns. If they don’t quarantine, you may need to quarantine at home before introducing it to your tank.

Bonus List:

Top 5 Things to Google Before Buying a Fish

1. What size tank does it need as an adult?

• A tiny juvenile might look perfect for your tank now, but some species grow way bigger than expected. Always check the adult size and make sure you have a tank large enough for the long term.

2. What’s its typical lifespan?

• Some fish (like clownfish) can live over 20 years, while others may only live a few years. Make sure you’re ready for the commitment before bringing one home.

3. Does it need any special care?

• Some fish require frequent feedings, specialized diets, or specific tank setups (e.g., sand beds for burrowing fish, rock caves for shy species).

4. Is it reef-safe?

• If you have corals or inverts, make sure the fish won’t eat, nip, or bulldoze them. Some fish, like angelfish and triggers, can be coral-nippers or invert predators.

5. Does it need a secure lid?

• Some fish (like wrasses and gobies) are jumpers and require a covered tank to prevent escape attempts.

Tamara’s Pro Tip: If you walk into a store and they can’t answer basic questions about the fish’s health and needs, that’s a huge red flag. Do your research and buy from reputable, knowledgeable sellers who care about their livestock!

Behavior & Compatibility: Will This Fish Get Along in Your Tank?

Before adding a new fish, it’s crucial to understand its natural behavior and how it will interact with your existing tankmates. Some fish are peaceful community members, while others are territorial nightmares. Here’s what to consider before making a purchase:

1. Understanding Behavior Types

• Peaceful Fish – These species coexist well with most tankmates, rarely showing aggression. Examples include clownfish (except maroon clowns), blennies, and firefish.
• Semi-Aggressive Fish – They’re usually fine in a mixed tank but may establish a territory and defend it, especially if they are added first. Think dwarf angelfish, some wrasses, and dottybacks.
• Aggressive Fish – These species tend to bully, chase, or attack tankmates, especially smaller or more passive fish. Some triggers, large angelfish, and certain tangs fall into this category.
• Shoaling & Schooling Fish – Some fish do best in groups (like anthias and chromis) and may become stressed or withdrawn if kept alone.

2. Choosing Compatible Tankmates

• Size Matters: A fish that’s small now may grow large and suddenly view smaller tankmates as food. Avoid mixing tiny fish with large predatory species.
• Temperament Matching: A tank full of peaceful fish won’t do well if you suddenly drop in an aggressive tank boss. Make sure temperaments align for long-term success.
• Tank Hierarchy: Some fish, like tangs and clownfish, establish a dominance order. Adding similar-sized or shaped species can lead to fighting for territory.
• Reef-Safe vs. Not: If you keep corals, research whether the fish is reef-safe or likely to nip at polyps, inverts, or clams.

3. Signs of Trouble After Adding a New Fish

• Chasing or Nipping – If an established fish won’t stop chasing the newcomer, you may need to rearrange rockwork or use an acclimation box.
• Hiding or Refusal to Eat – A fish that’s too stressed by aggressive tankmates may stop eating and become ill.
• Flared Fins & Posturing – These are warning signs of aggression before a fight breaks out.

4. Tips to Reduce Aggression in the Tank

• Add Peaceful Fish First: Introduce the most docile species before adding territorial fish.
• Use an Acclimation Box: This allows new arrivals to adjust to the tank without getting attacked.
• Rearrange Rockwork: This helps break up territories, reducing aggression from established fish.
• Feed Well Before Adding a New Fish: A well-fed tank is less likely to start fights over territory.

Tamara’s Pro Tip: If you’re ever unsure about compatibility, ask before you buy! Saves you the headache of tearing apart your aquascape to catch a troublemaker!

Conclusion: Be an Informed, Responsible Fish Keeper

Adding a new fish to your saltwater tank isn’t just about picking the one with the prettiest colors—it’s about making smart, informed decisions that ensure the long-term health of your tank. By asking the right questions before buying, researching the species thoroughly, and carefully considering compatibility with your current tankmates, you’ll avoid major headaches and create a more harmonious environment.

Patience is key. Impulse buys lead to problems like aggression, improper care, or even death, so take your time and plan ahead. Every fish has unique needs, and understanding them before you buy is the difference between a thriving aquarium and constant frustration.

Tamara’s Pro Tip: When in doubt, wait it out. If you’re not 100% sure a fish will work in your tank, sleep on it and do more research. A well-planned tank is a happy tank!

Happy Reefing!