If you are fascinated by marine aquariums, saltwater fish are a good way to get started in the hobby. Fish lie at the heart of any aquarium, but one needs to be careful about making fish choices, like their eating habits, temperament, and temperature requirements, if they are to thrive.
Whether you are a saltwater fish enthusiast or building your best beginner marine aquarium, knowing about the best salt water species can make all the difference. What makes salt water fish special is that they are easy to care for, adaptable, and beginner-friendly, so that you can easily master the art of maintaining a salt water tank.
For a full step-by-step system setup, see our guide From 10 to 150 Gallons: How to Build the Perfect Salt water Reef Aquarium.
What Makes a Good Beginner Salt water Fish?
The following characteristics make the best salt water fish for a Beginner salt water reef tank setup:
Hardy and Disease-Resistant
Beginner salt water fish do well when water conditions change slightly and have an in-built resistance against diseases like marine ich.
Easy to Feed Fish
Choose species that readily accept prepared foods like flakes, pellets, and frozen foods rather than those requiring live foods or specialized diets.
Peaceful Temperament
Aggressive fish can be stressful for both beginners and other tank mates. Sticking with community-friendly species is your best bet to
Small Adult Size
Fish that are no more than 4 inches in length are ideal for beginner tank sizes of 20-40 gallons, as they are low on maintenance and produce less waste.
Readily Available Saltwater Fish
Common species are easier to find, less expensive, and better researched for care requirements.
The Essential Ten: Best Saltwater Fish for Beginners
We have a curated list of the top 10 reef safe fish for you to begin with, before you bring your fish family home.
1. Ocellaris Clownfish Salt water Fish (Amphiprion ocellaris)
Often called the ‘False Percula’ or simply the ‘Nemo fish,’ Ocellaris Clownfish are widely considered the best saltwater fish for beginners due to their hardiness and adaptability.
Nearly all saltwater hobbyists are acquainted with these striking little fish with brilliant orange and white bodies and black-tipped fins.
Clownfish are far more forgiving of minor water parameter fluctuations than most other marine species. Beyond their resilience, they are also thoroughly captive-bred, which means they are easily attuned to aquarium life and foods, “people” movement.
A peculiar feature of clownfish is that they are gender-neutral and can thus change their sex depending on who they are paired with. Generally, the larger, more assertive saltwater fish will become the female, while the smaller remains the male. There is a wide variety of clownfish to choose from, such as the Maroon, Tomato, Clarkii, Percula, and Skunk.
Quick Stats:
- Min. tank size: 20 gallons (30+ for pairs)
- Adult size:3-4 inches
- Care level: Easy
- Reef safe: Yes – 100% coral safe
- Diet: Omnivore – frozen mysis shrimp, marine pellets, spirulina flakes, brine shrimp
2. Chalk Bass Salt water Fish
One of the most underrated gems of the Caribbean, the Chalk Bass saltwater fish (Serranus tortugarum) is a favorite reef safe saltwater fish for beginners because it combines sophisticated beauty with an incredibly peaceful demeanor.
It features a soft, pastel-blue body accented by distinct vertical indigo bars and a shimmering orange-to-pink dorsal area that glimmers under reef lightning.
While most groupers grow to massive, tank-busting sizes, the Chalk Bass stays a manageable 3 inches. However, it retains the high intelligence and curious “hovering” behavior of its larger cousins. In a large enough aquarium (55+ gallons), they can be kept in small groups where they can be seen hanging out together among the rockwork.
Quick Stats:
- Min. tank size:30 gallons (55+ for groups)
- Adult size:3 inches
- Care level: Easy
- Reef safe: Yes – coral and shrimp safe
- Diet: Carnivore – frozen mysis, enriched brine shrimp, high-quality pellets
3. Royal Gramma
The Royal Gramma ranks among the easiest saltwater fish for beginners thanks to its peaceful nature and resilience. On top of that, they can assimilate into life in small tanks of 20 gallons or more with only minimal care, making them well-suited to beginner tanks.
On the surface, they may look similar to the Royal Dottyback, but they are of a milder nature that gels easily with most tank mates, though they may pick a fight with fellow Grammas. A true deep-water fish, the gramma stands out for its brilliant purple and yellow body and tends to avoid bright light and instead hides away in caves or around rocks.
Quick Stats:
- Min. tank size: 20 gallons (30+ recommended)
- Adult size: 3 inches
- Care level: Easy
- Reef safe: Yes – completely coral safe
- Diet: Carnivore – frozen mysis shrimp, brine shrimp, marine pellet
4. Midas Blenny Reef Tank Fish
Look out for the midas blenny if you want to add a pop of personality to your tank. This easy saltwater fish comes in a golden-yellow body and is highly curious, which is why it can often be seen darting in and out of rock crevices. They are well-suited to thrive in small tanks of 30 gallons, provided the water conditions stay stable with plenty of hiding places.
Their diet mostly comprises a mix of algae and freeze-dried foods, but they may occasionally nibble on clams and corals if fed improperly. Other than that, they are mostly reef-safe, and their adaptability makes them a spectacular addition to a beginner’s saltwater setup.
Quick Stats:
- Min. tank size: 30 gallons
- Adult size: 4-5 inches
- Care level: Easy to Moderate
- Reef safe: Caution is required as they may occasionally nip at clams/corals if underfed
- Diet: Omnivore: algae-based foods, spirulina, mysis shrimp, marine pellets
5. Yellow Coris Wrasse Reef Fish
The yellow wrasse is a go-to option with its solid, neon-lemon body and a sleek, “cigar-shaped” body that adds both pop and dynamic movement to any tank. It is well-known as the legendary hunter of pests like Pyramidellid Snails, bristleworm, etc.
Unlike many other wrasses that can be “bullies,” the Yellow Coris won’t nip at your corals (SPS, LPS, or Softies), though it might snack on very tiny ornamental shrimp if it’s hungry.
They are incredibly resilient to minor saltwater fluctuations and are “diurnal,” meaning they are active and visible all day long, providing constant movement in the water column. They must be kept in a tank with a soft sand bed (at least 2 inches deep) to stay healthy and stress-free.
Quick Stats of Yellow Coris Wrasse Reef Fish:
- Min. tank size: 30 gallons minimum (40+ recommended)
- Adult size: 4-5 inches
- Care level: Easy
- Reef safe: Yes for corals; Caution with tiny shrimp
- Diet: Carnivore – frozen mysis, enriched brine shrimp, meaty foods; natural pest hunter
6. Yellow or Bluespotted Watchman Goby Salt water Fish
Whether you choose the sunny Yellow Watchman Goby (Cryptocentrus cinctus) or the shimmering Bluespotted Watchman Goby (Cryptocentrus pavoninus), Watchman Gobies bring a charismatic personality to any marine setup.
Both species share a fascinating relationship with the Alpheus pistol shrimp, where the shrimp digs and maintains a shared burrow, while the Goby looks out for any sign of danger. These gobies help keep the substrate healthy by oxygenating the sand bed and preventing the buildup of detritus.
Watchman Gobies are a perfect beginner marine aquarium fish as they are resistant to many common diseases, adapt quickly to prepared flake or frozen foods (like mysis shrimp), and generally stay out of trouble with other tank mates.
Quick Stats:
- Min. tank size: 30 gallons (40+ for bonded pair)
- Adult size: 3-4 inches
- Care level: Easy
- Reef safe: Yes – completely coral and invertebrate safe
- Diet: Carnivore – frozen/live mysis shrimp, enriched brine shrimp, sinking pellets
7. Pajama Cardinal Salt water Fish
The Pajama Cardinalfish (Sphaeramia nematoptera) is a quirky, colorful favorite with its spotted “pajama pants,” bold vertical band, and bright red eyes. They can often be found tucked near rockwork or branching corals or hovering almost motionlessly in the water column. In larger tanks, a small group of 3 to 5 creates a stunning “living art” effect.
This makes them an excellent choice if you are looking for a peaceful, relaxing tank dynamic rather than constant, frantic movement. While many saltwater fish are fiercely territorial, Pajama Cardinalfish are one of the few species that genuinely enjoy the company of their own kind.
Quick Stats of Pajama Cardinal Salt water Fish
- Min. tank size: 30 gallons (40+ for groups of 3-5)
- Adult size: 3 inches
- Care level: Easy
- Reef safe: Yes – 100% coral, clam, and anemone safe
- Diet: Carnivore: frozen mysis, enriched brine shrimp, small meaty foods
8. Blue Green Chromis
The Blue Green Chromis (Chromis viridis) is the quintessential “community builder” of the marine aquarium. Their shimmering scales shift between pale green and sky blue depending on the light, adding both natural movement and energy that few other species can match.
While most saltwater fish are solitary or territorial, Blue Green Chromis move in unison through the water column in a group of 5 to 7, which creates the dynamic “shimmer” effect seen in real coral reefs. Blue Green Chromis handle water fluctuations exceptionally well, making them an ideal hardy saltwater fish for a first-time hobbyist.
They will eagerly accept flakes, pellets, and frozen foods, and don’t come with a heavy bio-load of larger fish like Tangs. They are also known as “dither fish,” which encourages more timid fish like Blennies or Royal Grammas to come out of hiding.
9. Firefish Goby Reef Fish
The Firefish Goby stands out as an elegant, striking addition to any saltwater system. With a slender, pearlescent body and a brilliant gradient tail shifting from crimson to tangerine that flickers like a beacon, it is a masterpiece of natural design.
Because they rarely exceed 3 inches in length and have a very low bio-load, Firefish are the ultimate nano saltwater fish. Firefish make “good neighbors” for a community tank, as they don’t bother your corals, shrimp, and coexist perfectly with other gentle species like Pajama Cardinals or Royal Grammas.
Firefish are notorious “bolt-and-jump” fish and must be kept with a tight-fitting lid or mesh cover to prevent them from shooting upward at lightning speed if startled or feared.
Quick Stats:
- Min. tank size:20 gallons (30+ for pairs)
- Adult size:3 inches
- Care level: Easy to Moderate
- Reef safe: Yes – completely coral, shrimp, and invertebrate safe
- Diet: Carnivore – small meaty foods, frozen mysis, enriched brine shrimp, micro-pellets
10. Neon Gobby Fish
This hardworking, blue wonder is a favorite for both sleek desktop reef tanks and massive displays alike. Despite its small size, it exudes a subtle glow under reef lighting, making it easy to spot.
Neon Gobies excel in nano and Pico reefs (5-15 gallons) and produce almost no waste, which helps keep water stable. They love to “perch” on glass, rocks, or even your hand during maintenance, watching the world with curious eyes.
Moreover, they eat parasites, dead skin, and debris off the scales of larger fish, which helps keep the whole community healthy. Overall, they are well-adapted to aquarium life, less prone to disease, and support sustainable practices within the aquarium industry.
Quick Stats:
- Min. tank size:10 gallons
- Adult size: 1.5-2 inches
- Care level: Easy
- Reef safe: Yes – 100% coral and invertebrate safe
- Diet: Carnivore – frozen mysis, copepods, small meaty foods; natural cleaner fish
Once you’ve mastered these beginner-friendly species, explore truly unique additions in Exotic Saltwater Fishes That Stand Out in Aquariums.
The Best Saltwater Fish for 20 Gallon Tank
A 20-gallon tank is one of the most common beginner sizes. The good news? You can create a spectacular and stable setup with just a handful of species. If you plan to add corals, check out 10 Best Corals for Nano Tanks: Colorful & Hardy Picks.
Here’s a list of the best saltwater fish for 20 gallon tank:
- Clownfish (single or pair)
- Royal Gramma
- Firefish Goby
- Tailspot Blenny
- Yellow Watchman Goby
- Pajama Cardinalfish
- Orchid Dottyback (1 only)
If you are looking to start your own tank, don’t place more than 3–4 nano saltwater fish, as an overcrowded tank can upset the natural balance.
And if you’re starting your first setup, our Saltwater Fish Tank Kit for Beginners – The Saltwater Guide can help you choose the right equipment from day one.
5 Essential Tips for Keeping Hardy Salt water Fish as a Reef Tank Beginner
Here are our top recommendations to make your fish thrive in saltwater tanks.
1. Start Slow
Stocking too quickly is one of the biggest mistakes beginners make. Add 1 fish at a time, giving your tank a few weeks to initiate the nitrogen cycle before adding further.
2. Feed a Varied Diet
A varied diet consisting of quality frozen foods (mysis, brine shrimp), pellets with occasional treats of seaweed will keep your fish healthy and colorful. Avoid overfeeding as this can cause waste to build up.
3. Keep Up with Water Testing
The more stable the parameters, the more stable the fish. It’s essential to test regularly for nutrients like ammonia, nitrate, and nitrite weekly, especially during the first 3 months.
Learn more about water chemistry in The Science Behind Nano Tank Stability: Buffering, Alkalinity & Calcium.
5 Essential Tips for Keeping Hardy Salt water Fish as a Reef Tank Beginner
Here are our top recommendations to make your fish thrive in saltwater tanks.
1. Start Slow
Stocking too quickly is one of the biggest mistakes beginners make. Add 1 fish at a time, giving your tank a few weeks to initiate the nitrogen cycle before adding further.
2. Feed a Varied Diet
A varied diet consisting of quality frozen foods (mysis, brine shrimp), pellets with occasional treats of seaweed will keep your fish healthy and colorful. Avoid overfeeding as this can cause waste to build up.
3. Keep Up with Water Testing
The more stable the parameters, the more stable the fish. It’s essential to test regularly for nutrients like ammonia, nitrate, and nitrite weekly, especially during the first 3 months.
Learn more about water chemistry in The Science Behind Nano Tank Stability: Buffering, Alkalinity & Calcium.
4. Quarantine When Possible
When introducing new fish, it’s advisable to quarantine them for around 4 to 6 weeks to ensure they are healthy, disease-free, and eating well before joining your main display.
5. Top-off Daily
Freshwater evaporates, but salt does not. An Auto Top-Off (ATO) system can prevent unexpected salinity levels from spiking. You can also use a calibrated refractometer to keep salinity within the desired range of 1.025–1.026.
These simple habits will help your fish thrive, and your tank stay stable. For a full care routine, see How to Maintain a Saltwater Fish Tank.
Final Thoughts About Easy Salt water Fish for Reef Tanks
Building your first saltwater aquarium doesn’t have to be intimidating or stressful. Opting for peaceful, beginner-friendly, and hardy saltwater fish can help you realize your goal of a thriving, dazzling underwater world.
Every expert reef keeper once felt curiosity, excitement, and perhaps a bit of nervousness as they embarked on their saltwater tank journey. The difference between a struggling tank and a thriving underwater ecosystem often comes down to making the right choices, like the best saltwater fish, together with the right guidance and smart planning.
At ReefKG, we’re passionate about helping aquarists like you build healthy, sustainable marine ecosystems. Our AI-powered app provides personalized dosing alerts, real-time water parameter tracking, species compatibility guidance, and step-by-step care instructions tailored to your specific setup.
Download the ReefKG app today and join thousands of successful reef keepers who’ve transformed their saltwater dreams into reality.
1. What are the easiest saltwater fish for beginners?
The easiest beginner marine aquarium fish are Ocellaris Clownfish, Blue Green Chromis, and Pajama Cardinalfish because they are active, eat almost any prepared food, and are incredibly resilient. The Firefish Goby and Royal Gramma are other great options to add stunning color without requiring specialized care. Want even more beginner-friendly options?
2. How many saltwater fish can I keep in a 20-gallon tank?
In a 20-gallon “Nano” reef, the rule of thumb is 2 to 4 small fish, depending on their adult size and bioload. A perfect 20-gallon community might include a pair of Clownfish and a single Goby or Blenny. Overstocking leads to rapid waste buildup, so it is always better to start with fewer fish and prioritize a stable environment.
3. Are saltwater fish hard to keep?
Saltwater fish are not necessarily “harder” to keep than freshwater fish; they simply require more consistency to maintain stable levels of salinity and pH. Modern equipment like Auto Top-Offs (ATOs) and high-quality salt mixes make it easier than ever to maintain a saltwater reef tank.
4. What’s the hardiest saltwater fish?
The Damselfish (specifically the Azure or Yellowtail varieties) is widely considered the hardiest, but they can be aggressive. For a peaceful tank, the Ocellaris Clownfish and Neon Goby are remarkably “bulletproof” and far better suited for community life. These fish are known for their ability to bounce back from the minor “learning curve” mistakes many beginners make.
5. Can beginners keep saltwater tanks?
Absolutely! With the availability of captive-bred fish, pre-mixed saltwater, and “all-in-one” (AIO) aquarium kits, beginners can successfully maintain beautiful reef tanks. Check out 20 Best Saltwater Aquarium Fish for Beginner Reef Hobbyists.