Six line wrasses are small fish that need a lot of space. They’re also aggressive toward their own species and similar-looking wrasses. So a tank of 40 gallons or more is recommended for a single six line wrasse. You can keep a pair in a 75-gallon tank and multiple six line wrasses in a 150-gallon tank.
Let’s now understand the various factors that determine the tank size of six line wrasses in more detail.
5 Factors to Consider While Determining the Tank Size for Six Line Wrasses
Six line wrasses are energetic fish that can grow between 3 to 4 inches in length.
However, these reef-safe fish are hardy that need conditions similar to their natural habitat to thrive in aquariums.
Aquarium owners need to learn the specific needs of these fish when setting up an aquarium for them.
Other than their needs, other factors should also be considered when deciding their tank size.
Given below are some factors to consider while deciding on the right tank size for six line wrasses.
1. Number of Tank Inhabitants
The size of the aquarium is directly proportional to the number of fish you want to keep in it.
Six line wrasses are energetic small fish that need lots of space to swim and hide to protect themselves.
They’re shy and solitary fish that stay in a loose group in the coral reef.
You can keep a pair of six line wrasses in your marine aquarium.
You should also keep these wrasses with other reef-safe fish that can match their aggression and energy levels.
2. Size of The Fish
Six line wrasses can grow up to 3 to 4 inches in length. However, these fish shouldn’t be kept in nano tanks.
Lack of swimming space can make them territorial and aggressive.
Six line wrasses are also very aggressive during feeding hours and easily outcompete most tankmates.
So, to maintain peace, they must be housed in large aquariums.
3. Tankmates
Tankmates are another important factor to consider when deciding the tank size for six line wrasses.
These fish are compatible in a community aquarium with other peaceful fish.
They shouldn’t be kept with their own species or similar-looking peaceful wrasses.
Even with compatible tankmates, these fish need a lot of space to move around.
So the tank must be large enough to ensure that each fish has adequate room to swim freely.
Lack of space can lead to territorial disputes resulting in aggressive behavior and stress.
4. Tank Setup
Six line wrasses like to hang out near the bottom of the aquarium, feeding off the live rocks and hiding around the reef branches.
They should be kept in an environment similar to their natural habitat.
They’re also shy and like to hide to protect themselves.
So you can use caves and live rocks of different sizes to create hiding spots for six line wrasses.
Coral reefs can be used to imitate their natural habitat inside the tank.
However, with adequate protection, you must also consider an open swimming space while determining the tank size.
5. Tank Maintenance

Six line wrasses are hardy fish that can easily manage variations in water conditions.
However, like other marine fish species, stable water conditions can help these fish thrive in captivity.
Small tanks need a lot of effort to maintain stable conditions. A slight mistake can be hazardous to the tank’s inhabitants.
So, a large tank is a better option for these fish.
Regular tank maintenance also needs more effort and is time-consuming.
So buying a large aquarium can help save time and effort.
Can Six Line Wrasses Live in A Nano Reef Tank?
Six line wrasses are active and energetic fish that need lots of swimming space.
A nano reef tank can restrict their movements, making them aggressive toward other tank inhabitants.
These wrasses can also become territorial and begin chasing and attacking other fish due to lack of space.
Many fish owners often fail to understand this about six line wrasses.
The most common mistake is to house these fish in small tanks that restrict their movements.
Six line wrasses inhabit the coral reefs in their natural habitat.
These fish are known to forage around the reef branches and live rocks preying on small invertebrates and parasites.
So keeping them in small tanks can make these fish aggressive and territorial.
That’s why keeping six line wrasses in larger aquariums that offer more swimming space and hideouts is recommended.
How Many Six Line Wrasse Can You Keep in A 75-Gallon Tank?
Six line wrasses are peaceful fish. However, they become aggressive when housed with other similar-looking wrasses.
So it’s best to keep a single six line wrasse or a pair in a 75-gallon tank.
Six line wrasses are compatible with other peaceful marine fish species.
However, you must ensure that the tankmates can match the aggression and energy of the six line wrasses.
These fish enjoy exploring every corner of their environment for hidden morsels of food.
Moreover, having plenty of hideouts can also benefit other fish species by keeping them busy.
Six line wrasses also need a lot of swimming space because they’re very active and known to move around freely.
Besides a reef environment, having open space for these fish to swim around is essential.
Avoid keeping more than one pair of six line wrasses as the males will fight with each other.
Keeping them with other fish species in a 75-gallon aquarium is recommended.
How Many Six Line Wrasses Can You Keep in A 150-Gallon Tank?
Six line wrasses are shy and solitary fish. They swim in loose groups around the reef branches.
However, in a large 150-gallon tank, you can keep multiple male and female six line wrasses.
Male six line wrasses are aggressive toward other males of their own species or similar-looking wrasses.
However, the female wrasses can help diffuse the aggressive behavior.
Having said that, you can keep multiple male six line wrasses in a large 150-gallon tank as it will have sufficient space for each male wrasse to create his own territory.
Six line wrasses prefer plenty of swimming space and cover to hide, which big aquariums can easily accommodate.
Large aquariums also have enough space for you to imitate the natural environment of six line wrasses, making them feel comfortable and secure.
You can create an ocean reef environment by placing coral, live rocks, caves, and large invertebrates.
Don’t keep tiny invertebrates as they will become easy snacks of your six line wrasses.