best saltwater fish for nano tank

Starting saltwater aquariums is similar to freshwater aquariums in the sense that you must have a plan that includes knowing which are the best saltwater fish for nano tank. Check it out!

So what are the best saltwater fish for your nano tank?

When it comes to setting up a reef aquarium, you may want to start with a nano, or small sized tank. Choosing the right fish for a nano aquarium is extremely important because you will have a much smaller margin of error.

Author Note: If you can get it right, though, the rewards are huge! A nano reef tank is a beautiful and fun challenge for any fishkeeper.

What is a Nano Reef Tank? 

best saltwater fish for nano tank
Clownfish In A Colorful Anemone On A Tropical Coral Reef.

Nano reefs are found in aquariums 30 gallons or less. It’s possible to have five gallon nano reef, it’s not advised unless you are an expert.

Invertebrate inhabitants need to have perfect water quality and stable conditions. In a small tank this could be destroyed by accidentally feeding too much.

It’s also important for you to pick fish that can be compatible with nano reefs.

Author Note: The wrong fish will disturb and possible try to eat parts of the nano reef. Fish can see the reef as being a very convenient food source for when they need a snack between meals.

How to Choose the Right Fish for Your Nano Tank

As you get your nano tank set, consider these things as you pick your tiny fish for your tiny tank.

  1. Do the fish thrive in small spaces?

Top Tip: Look up each species and verify they do well in a nano tank – and whether or not they can be in a community tank.

  1. Do the fish prefer a planted tank or a tank with corals?
  2. How active are the fish? Will they blend well with their tank mates or will they be too active to get along together?
  3. Will they uproot plants?

the Top 15 Best Saltwater Fish for Nano Tanks

#1. Most popular best saltwater fish for nano tank: Stubby Ocellaris Clownfish

best saltwater fish for nano tank
Care Level
Easy
Tank Size20 gallons or more

Appearance

Slightly elongated, brilliant orange fish with white vertical stripes. They also have narrower black stripe divisions between the white and orange bands. 

Pros

Captive-bred Stubby Ocellaris Clownfish are readily available. They will accept meat as well as some frozen plant-based foods. 

Cons

Even though these fish are fairly peaceful, they also breed easily. Once the female lays eggs, both parents will defend the nest aggressively against other fish species in the tank. You may need to use dividers when eggs are in the tank. 

Summary

Overall, these are attractive fish that are slightly smaller than a full-sized Ocellaris Clownfish. As captive-bred fish, they are far more tolerant to home aquarium conditions and are more likely to thrive than wild captured fish.

On the downside, they are very likely to produce eggs, which can lead to aggression problems with other nano reef fish in the tank. 

We think they make one of the best saltwater fish for a nano tank.

#2. Unique best saltwater fish for nano tank- Hancock’s Blenny

best saltwater fish for nano tank
Care Level
Easy
Tank SizeMinimum 10 gallon tank

APPEARANCE

Hancock’s Blenny have slim, silvery yellow bodies with brown and black mottles that start behind their brilliant red eyes, and extend to the tail region.

Both tail and fins are transparent with light brown markings. Depending on the tank décor, this fish can easily hide itself in plain sight.

Pros

Hancock’s Blenny is a small size, agile fish that will get along easily with other peaceful fish. It also readily accepts frozen foods, and doesn’t tend to be picky about what kind of meat it has to eat.

Cons

When this fish is visible, it tends to dart around a lot to find food, and then it will go hide again. If you don’t have time to pay attention, you may miss out in this fish’s fascinating personality traits.

Summary

Overall, this is one of the easier saltwater fish to care for. It will do fine in a small nano reef tank, and is a good fish to start with.

That’s why its one of the best saltwater fish for your nano tank.

#3. White Banded Possum Wrasse

best saltwater fish for nano tank
Care LevelEasy
Tank Size10 gallons

Appearance

If you are looking for fish with markings on their iris, then you may have already heard of the Six-Line Wrasse. Unfortunately, this fish requires a much larger tank than the White Banded Possum Wrasse. 

The latter grows only 2 ½ inches long and has a dusty red body with vertical white stripes. Two white bands run through the fish’s irises, which are black with an inner red circle.

Finally, black eyespots rimmed in white on the upper and lower fins give this fish a mysterious and fascinating appearance without being over bright or overstated.

Pros

This is a fairly peaceful, small fish that will get along with its own kind as well as other species in the tank. Just be sure to keep one male and all the rest of the same species as females.

The White Banded Possum Wrasse does prefer live food, but it will also eat flakes and frozen foods such as worms. Since this fish does not consume corals, it also a good choice for nano reef tanks.

Cons

At first, this fish can be very shy, and may not come out of its hiding place for some time. It may also continue to hide if other fish in the tank are more aggressive.

This species of wrasse is also known to jump out of the water. Exercise care when opening up the tank for maintenance or other purposes. 

Summary

The White Banded Possum Wrasse is a fairly small, attractive, and peaceful fish that will work well in most nano tanks. Its color and patterns can make it stand out even among more dramatically colored fish.

#4. Helfrichi Firefish

best saltwater fish for nano tank
Care LevelEasy
Tank SizeThis fish will get about 2 ½ inches long, and will do best in a tank 20 gallons or larger

Appearance

This is an absolutely stunning long-bodied fish. It has a dash of bright yellow over its nose and extending back to about half the gill cover. After that, it switches rapidly to a strong violet that fades to a pastel, almost luminescent lilac.

Its caudal fin is tricolor with stripes of white, black, and red. Its anal fin is translucent, and then edged with yellow, blue, and orange. Finally, it has a pastel yellow tail with some lemon yellow striations. 

Pros

Color-wise, this fish is stunning without being obnoxiously bright. It will accept frozen foods and consume them in the water as well as from the substrate. This fish also gets along well with other peaceful species of a similar size.

Cons

As with many other marine fish, the Helfrichi Firefish does not get along with other members of its own species. Keep just one member to a tank unless you purchase a set of certified breeding fish.

Summary

This fish is fairly easy to care for (like Paradise Fish), and a good choice for beginners. While it may be territorial, it more than makes up for that with beautiful colors and a personality to match.

best saltwater fish for nano tank
Care LevelEasy
Tank Size20 gallons

Appearance

This is a very slim bodied fish that starts off with a lemon-colored head and dorsal fin. This coloring quickly fades to silvery white, and then gradually warms up to a carnation pink, and then bright salmon.

In the meantime, the dorsal and anal fins go from yellow to orange with horizontal black stripes. Finally, the Firefish Goby sports a moody black tail with orange markings. 

Pros

The Firefish Goby packs a lot of color into its slim, 3” long body. Although it will hide at first, once it gets settled in, this fish will display a personality as lively (yet non-aggressive) as it’s colors.

Cons

Although this fish is very intelligent, it also tends to be skittish. It will do fine as a mated pair in a tank, but will not get along with others of its own species.

Firefish Gobies will also try to jump out of tank if they feel stressed, or if they don’t have enough hiding places.

Aside from keeping a lid on the tank at all times, you may need to exercise care when removing the lid and sticking your hands in the water for maintenance purposes.

Summary

Overall, the Firefish Goby will do well in smaller tanks. It readily accepts frozen foods and will also clean up algae in the tank. Just be mindful of its tendency to jump and it skittish nature. 

It’s another great choice for the best saltwater fish for your nano tank.

#6. Neon Goby

neon goby
Care LevelEasy to moderate
Tank Size10 gallon or larger

Appearance

These are sleek, slim bodied fish with brilliant blue and black stripes. The neon goby also has a transparent, rounded tail and compact, transparent fins. 

Pros

These fish only reach about 2” in size at maturity. They get along with many other kinds of fish and tend to be hearty, so they will work well in a nano community tank.

You can also purchase captive-bred fish, which tend to do better in terms of accepting staple pellet and flake food. Since these fish are carnivores, however, you may still need to use live food to stimulate their appetite and promote good health. 

Cons

Among themselves, Neon Gobys may fight with each other. Since breeding pairs will not fight with each other, you may want to limit this fish to just two per tank as long as they are certified breeding pairs. 

Summary

The Neon Goby is well suited to smaller tanks and lends itself well to a community tank that may hold other peaceful fish and even hermit crabs.

This is also one of the few marine fish that will spawn in an aquarium setting, so you may be able to breed them if the conditions are right.

#7. Captive Bred Pajama Cardinalfish

Care LevelEasy
Tank SizeThis fish reaches about 3 ½ inches in size, and will do fine in a 30 gallon community tank

Appearance

At first glance, this fish’s shape is very similar to a freshwater Tiger Barb. It has one single vertical black stripe down the middle of its body, and then two yellow stripes on brilliant red eyes.

It’s nose and gill cover range from light green to yellow. Then, behind the black stripe, it is silver-colored with brown polka dots. It’s tail and rearward fins are transparent, while the dorsal and lower fins are yellow with red stripes. 

Pros

This fish schools well with members of its own species, and also gets along well with fish of other species. If you purchase captive-bred fish, they are more adaptable to frozen food and staple pellets or flake foods.

Cons

The Pajama Cardinalfish does not swim very quickly despite its fin shape and appearance. Therefore, it won’t do well in tanks with aggressive fish or larger ones that will see it as prey.

Summary

In terms of color and appearance, this is a personal favorite.

I can be kept in a single species tank, or in a community. It is an excellent choice for beginners as long as you are careful to choose tank mates that are peaceful and won’t try to chase it.

#8. Flameback Angelfish

flameback-angelfish
By © Citron, CC BY-SA 3.0
Care LevelMedium to difficult
Tank Size55 gallons or more

Appearance

In a sense, the Flameback Angelfish’s color pattern is the opposite of the Coral Beauty Angelfish.

Instead of having a dusky blue upper body with an orange mid area, the Flameback has a dark blue midsection rimmed in electric blue (like Blue Acara).

Since the Flameback only reaches 3” long at maturity, it is much better choice than the Coral Beauty which will grow to about 4”. 

Pros

If you are interested in keeping an angel fish in a nano tank, the Flameback Angelfish will fit into a tank considerably smaller than other related saltwater species. It easily accepts frozen plant and meat-based foods. 

Cons

As with other saltwater angelfish, the Flameback enjoys sampling corals and other plant-based creatures in the tank. It can also be fairly aggressive to other fish, however, this can be remedied somewhat by giving it plenty of places to hide. 

Summary

The Flameback Angelfish packs a lot of stunning colors into a relatively small body. Its interest in snacking on corals, however, can make it challenging to keep this fish in a true reef tank, nano or otherwise.

#9. Royal Gramma Basslet

Royal-Gramma-Basslet-1
Care LevelEasy
Tank Size30 gallon

Appearance

For a 3 inch long fish, the Royal Gramma Basslet packs in a lot of color. Starting at the head, this fish has a lovely violet coloring that fades into pink with yellow polka dots.

This yellow color solidifies and extends to the tail. The dorsal fin matches the body in terms of violet and yellow colors and then has one black dot in the front area of the fin.

Pros

This is a very attractive fish that gets along well with fish from other species provided they are of similar size and temperament. It will also accept frozen meat-based foods, however, it does enjoy hunting. 

Cons

This fish requires living nano reefs and must also have good hiding places. Since it is aggressive and territorial with fish from its own species, you may only be able to keep one fish per tank.

Summary

This is an absolutely stunning fish that will fit easily in a smaller home aquarium. It does, however, need a fully living coral system and cannot be placed with fish of its own species.

#10. Captive Bred Lemon Damsel

lemon-damsel
Credit to Rickard Zerpe (Flickr)
Care LevelEasy
Tank SizeThis fish will not get larger than 2.5 inches and will do fine in a 30 gallon community tank

Appearance

This fish’s coloring varies over its head, body, tail and fins from a lemon yellow to a soft peach. Body wise, it is similar to freshwater Skirt Tetras and other oval shaped fish. 

Pros

Gets along well with fish from other species and will not bother corals and other more fragile tank mates. Captive bred fish will also be easier to feed and are more tolerant of home tank water conditions. 

Cons

Even though it is territorial among fish of its own species, you can get around that by providing plenty of hiding places and a large enough tank. 

Summary

This is an attractive fish that will add some lovely colors to a small tank. It can be a bit territorial with members of its own species, so you may want to start with just one in a nano tank.

#11. Flagtail Shrimp Goby

flagtail-shrimp-goby
Credit to Rickard Zerpe (Flickr)
Care LevelEasy
Tank SizeEven though this fish is fairly long in length (5 inches) for a nano tank, it is slim enough to get along fine in a 30 gallon tank

Appearance

As with other gobies, the Flagtail Shrimp Goby has a long, slim body. Its main color is pearly white with brilliant orange stripes that fade gradually towards the underside of the fish.

This fish also has a rounded tail with bright yellow and orange markings. 

Pros

For the most part, this fish will stay near the bottom of the tank, leaving plenty of room to add other fish that swim in the mid to upper regions of the tank. It is also an attractive fish that accepts frozen food. 

Cons

The Flagtail Shrimp Goby is well known for jumping. If you want to keep more than one member of its species, it is best to purchase a certified breeding pair.

While this fish is peaceful with other species of fish, it is very territorial among its own kind. It will also eat small shrimp living in the tank. 

Summary

In a nano setting, this fish will thrive as long as you choose its tank mates carefully. Since it is known to jump out of the water, you will need a tight-fitting lid on the tank.

#12. Lyretail Blue Gudgeon Dartfish

Lyretail-Blue-Gudgeon-Dartfish
Care LevelEasy
Tank SizeEven though a 50 gallon or more tank will work better for this fish’s 6 inch length and need for large, open swimming areas, it will also get along in a 30 gallon nano reef tank

Appearance

This is a long-bodied, slim, slate blue colored fish with a slightly long tail. 

Pros

This fish is quite friendly and enjoys living in pairs with its own kind. It is known to be a very peaceful fish that will not bother other fish in the tank. 

Cons

This fish is known to jump, and may try to do so more often if the tank is too small. It also has a tendency to dig in the substrate.

Summary

Although this fish will accept frozen food, is friendly, and is easy to care for, it may not do well in smaller tanks. If you start with a 30 gallon tank, you may find that you need to move it into a 50 gallon aquarium or larger.

#13. Captive Bred Cave Transparent Goby

Captive-Bred-Cave-Transparent-Goby
Care LevelEasy
Tank SizeEven though this fish reaches about 3” in length, it is slim bodied enough to do well in a 10 gallon aquarium

Appearance

This is a long-bodied, brown freckled fish. Although it’s flesh is somewhat translucent, you may not be able to see its organs or food moving through.

Pros

As with other captive-bred species, this one will easily accept frozen foods. It is also fairly peaceful when interacting with fish of other species. 

Cons

Avoid keeping this fish with other gobies unless you introduce them to the tank at the same time. You can also try purchasing certified breeding pairs, or just keep one member of this species to a tank.

Summary

Overall, this is a fascinating fish that will get along well enough in a small nano reef tank. When purchasing captive-bred fish instead of wild-caught members, you will have a much better chance of succeeding in feeding and caring for it.

#14. Pygmy Coral Croucher Goby

Pygmy-Coral-Croucher-Goby
Care LevelEasy
Tank SizeThis fish only gets about 2 inches long, and will do well in a 10 to 20 gallon setup

Appearance

This is a somewhat oval, dusky orange-colored fish. It almost looks like a painting because of the way the colors blend and move across the body of this fish.

Pros

The Pygmy Coral Crocher Goby is a fairly outgoing and friendly fish once it gets established. It will seek to get to know you and learn as much as possible about the world outside its tank.

Cons

This a venomous fish that can sting both you and other inhabitants of the tank. You may also need to use a syringe to feed it on a daily basis. Even though it will accept frozen food, getting it to consume it may be challenging.

While it gets along readily enough with other fish, it will only accept a bonded mate when it comes to its own species.

Summary

In close quarters, venomous fish can be more stressed and more inclined to sting. It is very important to keep appropriate medications on hand.

As with bee stings, most venomous fish will not kill you unless you are allergic to the venom. 

#15. Hi-Fin Red Banded Goby

Hi-Fin-Red-Banded-Goby
Care LevelModerate
Tank SizeThis fish reaches about 2 inches long, and will do well in tanks 10 gallons or larger

Appearance

At first glance, this fish looks somewhat like an old-style barber pole or a candy cane, only it’s slanted stripes are vertical instead of horizontal.

This long-bodied fish also has a charming bright yellow nose and eyes. When combined with its long, black dorsal fin, it makes for an endearing creature.

Pros

This is a relatively peaceful fish when it comes to other species living in the tank. It will also accept frozen foods and staple flakes.

Cons

It may not get along with other fish of the same species. That being said, if you purchase certified pairs, they are highly likely to successfully breed in a home tank.

Summary

This fish can have a hard time adjusting to a home tank and may not eat at first, even if it is perfectly healthy and the water chemistry is right. Other than that, it is an attractive fish with a lot of personality.

What are the types of best saltwater fish for nano tank?

Here are some characteristics of fish that will work well in Nano Tanks.

Smaller Sized Fish

As a general rule, smaller fish require less food and produce less waste, which makes it easier for the tank to support the bioload.

When combined with the amount of space required for swimming and other activities, try to stay with fish that don’t get larger than 4” at maturity. 

Water Chemistry Tolerances for the best saltwater fish for nano tank

Many species of marine fish will only do well if they are kept in breeding pairs. They may not tolerate similar species let alone other pairs of their own kind. If you have a wider water chemistry range, it will be easier to find suitable tankmates.

Captive-Bred Fish

When fish are wild captured for the aquarium trade, there is no way to know their age, if they will be depressed because of mate loss, and other problems.

To add insult to injury, wild-caught fish usually require live food. 

While some captive-bred fish also require live food, there are many others that accept more widely available flakes, pellets, and frozen foods.

Author Note: When fish are raised in captivity, it may be easier to acquire certified pairs, which helps ensure compatibility.

Compatibility With Other Species

As with freshwater fish, some saltwater fish are more aggressive than others. Making sure all species in the tank are compatible is very important.

This includes making sure the fish will not over-consume live corals and other nano reef aquarium creatures. 

Food Requirements

Even though brine shrimp are very easy to raise, some species of fish may need other forms of live food in order to thrive.

In a similar fashion, fish that dine on reef-forming creatures can quickly spell disaster in a small aquarium.

It is best to find fish that will accept, at a minimum, frozen foods, as well as ones that won’t consume any corals you decide to keep in the tank.

Habitat Needs

In a freshwater tank, you can basically choose between habitats that include live plants and those that do not. When it comes to saltwater tanks, you have three options.

Author Note: You can choose a tank that no corals or exoskeletons in it (Fish Only Tank). 

Second, you may decide to purchase coral skeletons that will be used to house nitrifying bacteria. Since the corals themselves are not alive, the water chemistry requirements are not as complicated.

These tanks are referred to as FOWLR (fish only with live rock) tanks. 

Third, you may choose to place live coral polyps in the aquarium that will produce a reef during a normal part of their lifespan.

Of all the tank options, reef tanks are the most challenging with very little room for error. You will find that nano tanks may be even more challenging even if you set up a much larger accessory tank for the sump and refugium. 

Aquarium Region Preferences

If you choose nano fish that inhabit different parts of the aquarium, it may be possible to fit more species in the tank. 

Is the Species Venomous?

When I started planning my first saltwater tank, I was amazed by how many gorgeous aquarium fish produce poisons that can hurt humans.

Water maintenance often involves placing your hands and arms into a tank. The fish can easily see this as an invasion of their territory.

This can be deadly in a nano tank where there may be very little time for the venomous fish to get away from the perceived invasion.

Author Note: Considering how many other things you will have to get used to in caring for a saltwater tank, it is best to save venomous species for a later time when you can develop adequate safety measures for yourself and anyone else that might put their hands in the fish tank. 

Final Thoughts on best saltwater fish for nano tank

As the years have gone by, I have been amazed by the technological advances and captive breeding programs that make it possible to keep some species of marine fish in tanks as small as 10 gallons.

If you are ready to embrace a new challenge but don’t have a big budget, these smaller Nano Reef Tank might be an ideal option.

We hope you enjoyed our guide on the best saltwater fish for your nano tank!

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