12 Best Saltwater Fish for 55 Gallon Tank
Photo by Lisa Brewster on Openverse (CC BY-SA 2.0)
A 55-gallon saltwater tank is an ideal size for a beginner to intermediate hobbyist-large enough to maintain stable water chemistry, but manageable to set up and maintain. The key to success is choosing a mix of species that occupy different water levels, so your fish aren't all competing for the same space or food sources. Below are 12 hardy, compatible saltwater fish that work well in a 55-gallon setup.
Bottom-Dwelling Gobies and Blennies
These lower-level dwellers are workhorse fish that rarely compete with mid- or upper-level species. They're also among the most beginner-friendly saltwater fish you can choose.
Midas Blenny (Ecsenius midas)
The Midas blenny is a vibrant yellow, eel-like fish that reaches about 3 inches. It's highly recommended for beginners because it's an omnivore and eats readily from a variety of foods.
Key traits:
- Origin: Indian Ocean, Red Sea
- Needs plenty of caves and crevices to hide in
- Once acclimated, it becomes lively and will perch on rocks to observe the tank
- Stays in the lower tank level
Midas blennies are hardy and low-maintenance-once they claim a hiding spot, they become comfortable enough to spend time foraging around the aquascape.
Bicolor Blenny (Ecsenius bicolor)
Named for its striking coloration-brown front half, orange rear half-the bicolor blenny is a fascinating fish to watch, especially during feeding.
Key traits:
- Origin: Indo-Pacific
- Size: 3 inches
- Diet: Omnivorous
- Behavior: Darts quickly out of its cave to grab food, then "backs" into its den for safety
- Will eat a wide variety of foods
This fish is more tentative than the Midas blenny but offers endless entertainment as it makes quick raids for food.
Lemon Goby (Gobiodon citrinus)
The lemon goby is one of the most beautiful fish for a 55-gallon tank-bright yellow with blue streaks-but it's not as active as it is pretty.
Key traits:
- Origin: Indo-Pacific
- Size: 1.5 inches
- Diet: Carnivorous (prefers live brine shrimp)
- Behavior: Peaceful, content to loiter among decorations and plants
- Do not house with large, aggressive fish due to its small size
Lemon gobies can be trained to eat a variety of foods, but they have a well-known preference for live brine shrimp.
Neon Goby (Gobiosoma oceanops)
The neon goby is remarkable for two reasons: it's one of the few marine fish successfully bred in captivity, and it's a tireless cleaner fish.
Key traits:
- Origin: Western Atlantic
- Size: 1 inch
- Diet: Omnivorous
- Special role: Removes parasites from other fish-a crucial service in any tank
- Must be kept in a school of at least 5-6 fish
- Cannot cohabitate with predatory fish
- Lifespan: Only about 2 years, shorter than most aquarium fish
Keep neon gobies only in peaceful communities with plenty of hiding spots.
Orange-Spotted Goby (Valenciennea puellaris)
This sleek silver goby with neon-orange spots is popular among beginners for its hardiness and fascinating burrowing behavior.
Key traits:
- Origin: Indo-Pacific
- Size: 4 inches
- Diet: Omnivorous, easily fed
- Behavior: Loves to dig and burrow into substrate
- Ideal for tanks with a sandy bottom
Orange-spotted gobies will devour a wide range of foods and are excellent for beginner tanks.
Blue-Cheek Goby (Valenciennea strigata)
The blue-cheek goby is another hardworking bottom-dweller that actively roots through substrate.
Key traits:
- Origin: Western Pacific, Indian Ocean
- Size: 3 inches
- Diet: Omnivorous
- Special role: Acts like a living vacuum, cleaning detritus from gravel
- Peaceful and can be kept in pairs
Blue-cheek gobies are ideal for under-gravel filters because they'll pick off debris that would otherwise clog your system. They're so good at what they do, many aquarists keep two.
Mid- and All-Level Wrasses
Wrasses are active, colorful, and crucial to a vibrant community tank. However, many species become larger and more aggressive as they mature. Choose juveniles when possible, and be prepared to monitor temperament as they grow.
Spanish Hogfish (Bodianus rufus)
The Spanish hogfish is a member of the wrasse family that can grow to 8 inches and occupy all tank levels.
Key traits:
- Origin: Western Atlantic
- Diet: Omnivorous
- As juveniles: Peaceful, hardy, and serve as cleaners
- As they mature: Become more aggressive and may eat smaller fish
- Coloration changes with age, becoming more red over time
Young Spanish hogfish are excellent beginner fish. However, some experienced aquarists move them to a separate tank once they outgrow the community, since mature individuals can dominate a 55-gallon setup.
African Clown Wrasse (Coris formosa)
The African clown wrasse undergoes dramatic color changes as it matures, starting with white stripes that turn blue-green.
Key traits:
- Origin: Indo-Pacific, Red Sea
- Size: 8 inches
- Diet: Carnivorous, prefers live food and meaty fare
- Behavior: Keep only one per tank-they fight among themselves
- As juveniles: Peaceful with smaller fish, but become combative with age
- Feeds at the bottom level
This fish prefers live invertebrates like brine shrimp, though it will accept other meaty foods.
Cleaner Wrasse (Labroides dimidiatus)
The cleaner wrasse is one of the most popular saltwater aquarium fish in the world for good reason: it's a hardworking cleaner, small, and peaceful.
Key traits:
- Origin: Indo-Pacific
- Size: 2 inches
- Diet: Carnivorous (feeds on parasites, but needs supplemental marine foods)
- Special role: Removes parasites from the body, gills, and mouth of other fish
- Occupies all tank levels
- Can be kept with other cleaner wrasses
This is a must-have for the novice saltwater aquarist. It gets part of its nutrition from cleaning other fish, but you should offer a variety of supplemental marine foods to keep it healthy.
Four-Spot Wrasse (Halichoeres trispilus)
The four-spot wrasse is one of the most beautiful wrasses available-an intense yellow body marked with four distinctive black spots along its spine and tail.
Key traits:
- Origin: Indian Ocean
- Size: 4 inches
- Diet: Carnivorous, readily eats meaty marine foods
- Behavior: Very peaceful, ideal for beginners
- Occupies all tank levels
This fish is an excellent choice for anyone new to saltwater aquariums, and it remains peaceful throughout its life.
Middle-Level Specialists
Yellow Sweetlips (Plectorhynchus albovittatus)
The yellow sweetlips is perfect for a peaceful community tank with its vibrant yellow and white stripes-though the colors fade somewhat with age.
Key traits:
- Origin: Indo-Pacific, Red Sea
- Size: 4 inches
- Diet: Carnivorous (meaty marine foods)
- Tank levels: Middle and lower
- Behavior: Shy around very active or hyperactive fish; benefits from a calm community
- Hardy once established
Yellow sweetlips prefer a quiet environment and may retreat if housed with overly active species. Their bright colors eventually become more muted and brownish with age.
Dwarf Angelfish (Centropyge species)
While full-size angelfish grow too large and aggressive for a 55-gallon tank, dwarf angelfish solve this problem beautifully.
Key traits:
- Origin: Atlantic, Pacific, Indian Oceans
- Size: 3 inches
- Diet: Omnivorous
- Behavior: Peaceful, non-aggressive, don't fight with other dwarf angelfish
- Tank levels: All levels
- Can be kept in pairs
- Compatible with many marine invertebrates
Dwarf angelfish are much less aggressive than their larger cousins, can cohabitate peacefully, and are suitable for tanks planning to add invertebrates. Provide plenty of caves and decorations to give them refuge, but leave enough open space for swimming.
Stocking Your 55-Gallon Tank: Practical Tips
Plan for All Water Levels
A 55-gallon tank has distinct water zones:
- Lower level: Gobies, blennies, bottom-feeding wrasses
- Middle level: Yellow sweetlips, some wrasses
- Upper level: Small wrasses, some angelfish
By choosing species for each zone, you avoid overcrowding in any single area and reduce competition for food and shelter.
Research Before You Buy
The species listed here are generally hardy and beginner-friendly, but every fish has specific needs:
- Talk to trusted aquarium shop professionals or online communities
- Research water chemistry requirements (salinity, pH, temperature)
- Understand compatibility before mixing species
- Know the adult size and temperament of your fish, not just their juvenile appearance
Account for Growth and Maturation
Several species on this list-particularly Spanish hogfish, African clown wrasse, and angelfish-become more aggressive or outgrow a 55-gallon tank as they mature. Be prepared to:
- Move fish to a larger tank if needed
- Establish a separate species tank for problem fish
- Understand that some fish are best kept singly
Tank Setup Essentials
Before stocking any of these species, ensure your tank has:
- Adequate live rock and cave systems for hiding
- A sandy substrate if you're keeping burrowing gobies
- A protein skimmer for water quality maintenance
- Proper quarantine procedures for new arrivals
- Stable salinity, pH, and temperature (most saltwater fish prefer 72-78°F)
Compatible Combinations
Not all 12 fish belong in the same tank-a 55-gallon tank typically holds 6-10 fish comfortably. A successful mix might look like:
- Lower level: One orange-spotted goby + one blue-cheek goby (they complement each other)
- Lower level: One Midas blenny or bicolor blenny
- Mid/all levels: One cleaner wrasse + one four-spot wrasse
- Mid level: One yellow sweetlips
- Upper/all levels: One or two dwarf angelfish
Avoid combining multiple wrasses of the same species, and keep only one African clown wrasse if you include that species. Always skip species known to be aggressive predators if you want to include small, peaceful fish.
Final Thoughts
A 55-gallon saltwater aquarium is large enough to house a diverse, colorful community but small enough to remain manageable. The fish listed here are proven community members that thrive when paired thoughtfully. Spend time researching the exact species you're interested in-especially as they mature-and don't hesitate to talk with experienced aquarists or your local shop. The more you understand your fish's wild origins and natural behavior, the better you can recreate a habitat where they'll truly flourish, and the more enjoyment you'll get from the hobby.
Frequently asked questions
Can I keep all 12 of these fish in one 55-gallon tank?+
No. A 55-gallon tank is typically comfortable for 6-10 fish total, depending on their adult size and bioload. Choose compatible species from different water levels (blennies and gobies at the bottom, wrasses throughout, angelfish in upper and mid areas) rather than trying to house all 12 species together. For example, avoid keeping multiple wrasse species of the same genus, and never house more than one African clown wrasse in the same tank.
Which of these fish are best for absolute beginners?+
Midas blenny, bicolor blenny, orange-spotted goby, blue-cheek goby, cleaner wrasse, four-spot wrasse, and dwarf angelfish are all excellent for beginners. They're hardy, eat readily, and are forgiving of small mistakes in water chemistry. Start with one or two of these, get comfortable with your tank's routines, and add more species only after you've established stable conditions.
Why do some of these fish become aggressive as they grow?+
Spanish hogfish, African clown wrasse, and full-size angelfish (though we recommend only dwarf species for a 55-gallon tank) are natural predators that feed on small fish and invertebrates in the wild. As they mature and grow, their predatory instincts intensify, and they may eat smaller tankmates or become territorial. If you start with juveniles, monitor their behavior closely and be prepared to move them to a larger tank or species-only setup if aggression develops.
Do I need live food for these fish?+
Most of these species will accept frozen or prepared marine foods, but some have a preference for live food. Neon gobies, lemon gobies, and African clown wrasse prefer live brine shrimp. You can culture your own brine shrimp inexpensively, or buy frozen alternatives that many fish will accept once acclimated. Start by offering a variety of foods-pellets, flakes, frozen mysis shrimp, and frozen brine shrimp-and observe what your fish eat most readily.
How often should I feed these fish, and how much?+
Feed most of these fish once or twice daily, offering only what they can eat in 2-3 minutes. Overfeeding is a common beginner mistake that fouls water quality. The neon goby eats parasites off other fish, so it gets supplemental nutrition from its cleaning role, but should still be offered regular foods. The blue-cheek and orange-spotted gobies spend much of the day foraging in the substrate, so they may seem to need less frequent feeding than actively hunting wrasses.
Can these fish be kept with a reef or live coral?+
Most of these fish are reef-safe or reef-compatible, but dwarf angelfish are the most predictable. Some wrasses, especially as they mature, may pick at or eat small invertebrates. If you plan to add corals or invertebrates later, stick with dwarf angelfish, cleaner wrasse, and the smaller gobies and blennies, and avoid larger species like Spanish hogfish and African clown wrasse. Always research the specific species you choose before mixing them with invertebrates.