Best Saltwater Fish for Your 90 Gallon Tank

Despite being large in size, these fish tanks cannot host every saltwater fish or reef aquarium species, but they certainly can hold the majority.

Before we dive into the list, we must consider the common 90-gallon tank dimensions and weight to ensure you are aware and happy with the size of the aquarium to reside in your home.

Classic 90 Gallon Saltwater Fish Tank Dimensions and Weight

90-gallon fish tanks share almost the exact same dimensions as the standard 75-gallon fish tank. However, the difference is the depth, 90 gallon aquariums are 3 inches (7.6 cm) deeper.

The dimensions for a 90-gallon saltwater fish tank are 48 inches (121 cm) long x 18 inches (46 cm) wide x 24 inches (61 cm) deep. Below is a graphical representation of these dimensions.

When it comes to the weight of a 90-gallon fish tank, you must consider the weight before and after the tank has been filled with water.

So, with that in mind, a 90-gallon aquarium will weigh about 160 pounds (72 kg) and over 1000 pounds (453 kg) when full of water.

Here are the 15 Best Saltwater Fish for a 90 Gallon Tank

1. Yellow Tang (1 Fish)

Yellow tangs are without a doubt a favorite here at Lionfish Lair, they are chilled out by nature and showcase a unique body shape, not to mention a striking yellow coloration that draws attention from just about anyone. Check out our yellow tang care guide for more in-depth information.

  • Temperature: 72 to 82°F (22 - 28°C).
  • Diet: Yellow tangs are omnivores, requiring a balanced diet of fish and meats, with vegetables and plant matter.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 8 inches (20 cm) in length.

2. Convict Tang (1 Fish)

Convict tangs are another popular tang species, who suite a 90-gallon aquarium perfectly, due to their larger size and busy swimming habits. These tangs get their name from their black and white stripy bodies. They are semi-aggressive, so, don't house them with small and timid fish.

  • Temperature: 72 to 79°F (22 - 26°C).
  • Diet: Convict tangs are omnivores, requiring a balanced diet of fish and meats, with vegetables and plant matter.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 8 inches (20 cm) in length.

3. Mimic Lemon Peel Tang (1 Fish)

Mimic tangs are a truly beautiful surgeonfish, showcasing an abundance of tropical patterns and colorations. Just like their convict counterparts, they are semi-aggressive fish that can either play well and be a peaceful community member, or become a bully. So, choose their tank mates with caution and also do not keep more than one in the same tank.

  • Temperature: 72 to 78°F (22 - 25°C).
  • Diet: Mimic lemon peel tangs are herbivores, requiring only plant-based foods to maintain a healthy diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 8 inches (20 cm) in length.

4. Exquisite Wrasse (3 - 5 Fish)

Exquisite wrasses really do live up to their name, they are truly stunning fish that showcase bright red, blue, and green colors in an almost neon appearance. They are considered to be one of the least aggressive wrasse species as well, considered to be a peaceful fish and model citizen.

  • Temperature: 72 to 78°F (22 - 25°C).
  • Diet: They are carnivores, requiring only meat-based foods to maintain a balanced and healthy diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 5 inches (13 cm) in length.

5. Mystery Wrasse (3 - 5 Fish)

Mystery wrasses truly do live up to their name - their appearance is a genuine mystery! They have a conventional wrasse bodyshape, however, that is where the comparisons end. Their bodies are bright pink with thin white lines travelling down, bright blue fins and tail, and a neon yellow face. Their peaceful personalities and amazing appearance make them well-suited to a 90-gallon saltwater aquarium.

  • Temperature: 72 to 78°F (22 - 25°C).
  • Diet: They are carnivores, requiring only meat-based foods to maintain a balanced and healthy diet.
  • pH Level: 8.0 to 8.4.
  • Maximum Size: 5 inches (13 cm) in length.

6. Flame Angelfish (3 - 5 Fish)

Flame angelfish are always a safe bet for populating larger salwtater fish aquariums. But now you can add up to 5 if you wish! Their entertaining and interesting behavior, not to mention mezmorizing appearance make them a fantastic choice for you. However, they are semi-aggressive, but from our experience, they certainly can be peaceful fish.

  • Temperature: 72 to 78°F (22 - 25°C).
  • Diet: They are carnivores, requiring only meat-based foods to maintain a balanced and healthy diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 4 inches (10 cm) in length.

7. Dispar Anthias (1 Fish)

These peaceful fish will make for a fantastic addition to your aquarium, they are brightly colored and truly beautiful reef compatibel fish.

  • Temperature: 72 to 78°F (22 - 25°C).
  • Diet: They are carnivores, requiring only meat-based foods to maintain a balanced and healthy diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 4 inches (10 cm) in length.

8. Blue Reef Chromis (1 - 5 Fish)

Blue chromisfish are certainly a fan favorite, and for good reason too. Not only are they peaceful fish that can be kept in larger groups, but their bright blue coloration and awesome body shape makes them a sight to behold.

  • Temperature: 75 to 82°F (25 - 28°C).
  • Diet: They are omnivores, requiring a balanced diet of both vegetables and meats.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 5 inches (13 cm) in length.

9. Blue Tang (1 Fish)

Another fan favorite due to their appearance in the popular movie franchise "Finding Nemo", blue tangs are showcase a beautiful coloration of blue, black, and yellow. They are peaceful but have been known to be semi-aggressive in some instances.

  • Temperature: 72 - 82°F (22 - 28°C)
  • Diet: They are herbivores, requiring plant-based foods to maintain a healthy diet. You should also feed them algae once or twice a week.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 12 inches (30.5 cm) in length.

10. Azure Damselfish (1 Fish)

Azure damselfish are one of the easiest damselfish to care for, no matter what level of experience you are. Their bodies are bright blue and they display an almost neon yellow belly. Like most damselfish, they are semi-aggressive, so, you must ensure they are living with compatible fish.

  • Temperature: 72 - 78°F (22 - 25°C)
  • Diet: They are omnivores, requiring a mixture of both plant and meat-based foods to achieve a balanced diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 3 inches (7.62 cm) in length.

11. Flame Hawkfish (1 Fish)

Flame hawkfish are unusual yet beautiful fish. They showcase a bright red body with a dark blue color running along their spine. They are also naturally peaceful fish and easy to care for, spending most of their time residing at the bottom of the tank.

  • Temperature: 72 - 78°F (22 - 25°C)
  • Diet: They are omnivores, requiring a mixture of both plant and meat-based foods to achieve a balanced diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 4 inches (10 cm) in length.

12. Banggai Cardinalfish (1 - 5 Fish)

These cardinalfish are incredibly popular and super easy to look after too, their bodies are shaped rather oddly too, which adds to their uniqueness. They display a stipy pattern and can be kept in larger groups, with 5 being the maximum for a 90-gallon aquarium.

  • Temperature: 73 - 84°F (23 - 29°C)
  • Diet: They are carnivores, requiring meat-based foods to achieve a balanced diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 3 inches (8 cm) in length.

13. Yellow Stripe Cardinalfish (1 - 5 Fish)

Yellow cardinals are peaceful community fish that enjoy the company of their own species (pretty rare for a fish on this list). Their golden/yellow bodies are awesome and they enjoy swimming around in groups or solo.

  • Temperature: 72 - 78°F (22 - 25°C)
  • Diet: They are carnivores, requiring meat-based foods to achieve a balanced diet.
  • pH Level: 8.1 to 8.4.
  • Maximum Size: 2 inches (5 cm) in length.

We understand that 90-gallons is a rather large aquarium, and many people simply do not have the space, time, or budget to afford a fish tank of this size. So, why not check out some of our other fish recommendations for some of the smaller tank sizes:

Here are the Saltwater Fish that need 90 Gallons or more

Every fish has a minimum tank size requirement, this is so they do not end up residing in an undersized tank, which will result in a plethora of health problems, typically resulting in a much shorter life and incredibly distressed fish.

That being said, there are some fish that require a 90-gallon fish tank or more to live a healthy life. So, here are some saltwater fish that you have unlocked due to them requiring a minimum tank size of 90 gallons:

  • Mimic Tang
  • Exquisite Wrasse
  • Mystery Wrasse
  • Bluehead Wrasse
  • Katherine's Wrasse
  • Scott's Wrasse

90-Gallon Saltwater Fish Tank Equipment

It's all well and good knowing the fish to populate your new 90-gallon saltwater tank, but it is equally, if not more important to know what equipment you need in order to run a healthy aquarium.

Here are some advisories:

  • A 300-watt heater, but two 200-watt heaters would be even more effective.
  • A protein skimmer for filtration.
  • Aquarium lighting for creating a realistic atmosphere, keeping your fish calm.
  • A secure lid to stop your fish from jumping out.
  • A powerhead or two, creating consistent water flow.
  • Multiple water quality testing kits.

Final Thoughts

90 gallon fish tanks are the perfect size for a hobbyist seeking a new and (literally) bigger challenge! Fortunately, due to the generous size of the aquarium, you have many fantastic options when fish are concerned. That is where this list comes into play, all of the fish that feature are more than compatible with a 90-gallon tank, and with each other. Making your life a lot easier when looking for the right fish to fill it up with.