Northern sunfish Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: December 17, 2022

The Northern sunfish is a beautiful and unique freshwater fish that is perfect for any beginner aquarium.

This fish is very peaceful and can be kept with a wide variety of tank mates. They are also very easy to care for and are very tolerant of a wide range of water conditions.

The Northern sunfish is a perfect fish for any beginner aquarist.

Species overview

The Northern sunfish (Lepomis gibbosus) is a freshwater fish that is native to parts of North America. It is most commonly found in the Great Lakes region but can also be found in smaller ponds and lakes throughout the United States and Canada.

This fish gets its name from the fact that it is often found basking in the sun near the surface of the water. It is a relatively small fish, only growing to be about 10 inches in length.

The Northern sunfish is a popular choice for aquarists because it is a hardy fish that is easy to care for. It is also a peaceful fish that can be kept with a variety of other freshwater fish.


Northern sunfish

The Northern sunfish is a small and stocky freshwater fish. They have a very compressed body that is deep and short. This gives them a very round appearance when you look at them from the top.

Their dorsal and anal fins are both small and rounded. They have a very small caudal fin that is also rounded. Their pelvic and pectoral fins are also small.

The color of the Northern sunfish can vary quite a bit. They can be brown, green, yellow, or some combination of these colors. They usually have some darker spots on their body as well.

The underside of the Northern sunfish is usually lighter in color than the rest of their body.


The average lifespan of a Northern sunfish is about 4 years. However, there are a number of factors that can impact their lifespan.

For example, if they’re kept in captivity then their lifespan will be shorter than if they were in the wild. This is because they’re not used to the stressors of captivity.

The level of care they receive also matters. If they’re kept in poor conditions then their lifespan will be shorter than if they were in optimal conditions.


Northern sunfish can grow to be about 12 inches long, but are more commonly around 8 inches. Females are typically larger than males.


Tank Size

The recommended tank size for a single sunfish is 30 gallons. If you want to keep more than one fish, you’ll need to add at least 10 gallons for each additional fish.

While sunfish can technically survive in smaller tanks, they will be much happier and healthier in a larger tank where they have plenty of space to swim around.

Water Parameters

Northern sunfish are a type of freshwater fish that is native to North America. They are found in lakes, ponds, and streams with slow-moving water.

The ideal water temperature for northern sunfish is between 70 and 75 degrees Fahrenheit. The pH level should be between 6.5 and 7.5, and the water hardness should be between 4 and 10 dGH.

It is important to maintain consistent water parameters for northern sunfish. They are sensitive to changes in their environment and can become stressed easily. sudden changes in temperature, pH, or hardness can cause problems for northern sunfish, so it is important to test the water regularly and make gradual changes if necessary.

  • Water Temperature: 70-75 degrees Fahrenheit
  • pH Levels: 6.5-7.5
  • Water Hardness: 4-10 dGH
  • Alkalinity Levels: Not required

What To Put In Their Tank

When it comes to the interior of their tank, these fish are pretty flexible. They don’t have any strict requirements and will do well in a variety of setups.

One thing we recommend is a sandy substrate. This will be more comfortable for them and make it easier for them to find food.

You can also include some plants if you want. These fish aren’t known to eat plants, but they might nibble on them a bit. Hardy plants like Hornwort or Java Fern are a good choice.

Rocks, driftwood, and caves are all good additions to their habitat as well. These fish like to have places to hide and feel safe, so giving them a few options is a good idea.

Just avoid putting too much in their tank. These fish need some room to swim and don’t do well in cramped spaces.

Common Diseases

The northern sunfish is a hardy fish that doesn’t usually fall ill. However, there are still some diseases that you need to be aware of.

The most common disease that affects this species is ich. This is a parasite that will attach itself to your fish and cause white spots to form on their skin.

If left untreated, ich can be fatal. However, it’s relatively easy to treat if you catch it early. The most important thing is to maintain good water quality in your tank.

Another disease to look out for is hole-in-the-head disease. This is caused by poor water quality and the presence of activated carbon in the tank.

It will present itself as pits or holes in the head of your fish. While it’s not usually fatal, it can be quite difficult to treat.

The best way to prevent these diseases is to maintain a clean and stable tank. This will keep your fish healthy and reduce the chance of them getting sick.

Behavior & Temperament

The northern sunfish is a relatively peaceful fish that doesn’t bother other tank mates. They’re also not known to be territorial, so you shouldn’t have any issues with them fighting with each other.

These fish are mostly bottom-dwellers, but they will occasionally swim up to the surface to feed. They’re not fussy eaters and will accept most types of food, including pellets, flakes, and live/frozen foods.

One thing to keep in mind is that northern sunfish are escape artists. They’re known to jump out of tanks, so be sure to keep a lid on your tank!

Tank Mates

Northern sunfish are a great option for community tanks. These fish are relatively peaceful and get along well with other species.

That said, there are a few things to consider when choosing tank mates for a northern sunfish.

First, these fish are on the larger side. They can reach up to 12 inches in length, so you’ll need to choose tank mates that are large enough to not be seen as food.

Secondly, northern sunfish are known to be a bit nippy. They’re not aggressive, but they may nibble on the fins of other fish.

This is usually only a problem with slow-moving fish or those with long fins. As a result, you’ll want to avoid fish like bettas and angels.

Finally, northern sunfish prefer cooler water. They’re native to lakes and streams in North America, so they’re accustomed to water temperatures in the 60-70 degree Fahrenheit range.

With all of that in mind, here are some compatible tank mates for northern sunfish:


The northern sunfish is a fairly easy fish to breed. They are livebearers, so the fry will develop inside the female and be born alive.

To start the breeding process, you will need to have a male and a female sunfish. The easiest way to tell them apart is by their size. The males are typically smaller than the females.

Once you have your male and female, you will need to set up a breeding tank. The tank should be at least 20 gallons. It should also have a tight-fitting lid to prevent the sunfish from jumping out.

Place some plants in the tank for the sunfish to hide in. Java moss is a good option. You will also need a sponge filter.

Fill the breeding tank with water that is the same temperature as the water the sunfish are currently living in.

Once the breeding tank is set up, you can add the sunfish. The female will usually start to produce fry within a week.

The fry will be born alive and be able to swim and feed on their own. You can feed them baby brine shrimp or crushed flake food.

As the fry grow, you will need to move them to a larger tank. They can be moved to the main tank once they are big enough to not be eaten by the other fish.


The Northern Sunfish is a great choice for anyone looking for a hardy and easy to care for fish. They are a great addition to any community tank and will do well with a variety of different tank mates.

They are also a great choice for beginner fish keepers as they are very easy to care for and are very tolerant of a wide range of water conditions.

Overall, we think the Northern Sunfish is a great choice for anyone looking for a fun and easy to care for fish!