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

Updated: December 17, 2022

The green sunfish is a beautiful and popular freshwater fish that is perfect for beginners. They are easy to care for and can be kept in a wide range of tank sizes.

Green sunfish are also very peaceful fish and get along well with other tank mates. In this guide, we will teach you everything you need to know about green sunfish care.

Species overview

Green sunfish (Lepomis cyanellus) are a type of freshwater fish that are native to various parts of North America. They can be found in slow-moving rivers, streams, and lakes.

Green sunfish prefer areas with a lot of vegetation, as this provides them with places to hide and ambush their prey. They are opportunistic feeders and will eat just about anything they can fit in their mouth, including other fish, insects, and crustaceans.

Green sunfish are a popular choice for aquariums and ponds, as they are relatively easy to care for and are not too aggressive. However, they can grow quite large (up to 12 inches in length), so it is important to make sure you have a tank that is big enough to accommodate them.


Green sunfish

The first thing you’ll notice about this fish is their color. As the name implies, they have a very green hue to their body. This can be a bit brighter or more subdued depending on the variety. The green coloration is broken up by vertical bands that are a dark black.

You may also notice that the belly of this fish is a creamy white color. This is in stark contrast to the rest of their body and really makes them stand out.

The second thing you’ll notice is their unique shape. Green sunfish have a very deep and compressed body. This gives them a very round appearance when you look at them from the top or bottom.

Their dorsal fin is tall and starts about two-thirds of the way back on their body. The anal fin is much shorter and starts closer to the middle of the fish. Both of these fins are rounded at the end.

The caudal fin is forked and quite tall, almost as tall as the dorsal fin. The caudal peduncle is very thin which makes the fish look like they have a long tail.

Green sunfish have rather small mouths that point downwards. This is in contrast to their large eyes that sit fairly high up on their head.


The average lifespan of a Green sunfish is 2 to 3 years.

As with most fish, there are a number of factors that can impact the lifespan of a Green sunfish. If they are kept in poor water conditions or are stressed from bad tank mates, their lifespan will be on the lower end of this range.

Conversely, if they are well cared for and have ideal living conditions, they can live closer to the upper end of this range.


The average green sunfish size is about 4-6 inches when they are fully grown. However, they can sometimes grow to be as big as 8 inches!


Tank Size

The recommended tank size for green sunfish is 30 gallons. If you’re looking for a smaller freshwater fish that can fit in an average-sized tank, this is a good option.

You can keep more than one green sunfish in the same tank as long as you provide enough space. For every additional fish, you should add 10 gallons to the tank size.

Water Parameters

The green sunfish is a freshwater fish that is native to North America. They are closely related to the bluegill and can be found in a variety of habitats, from streams and rivers to ponds and lakes.

Green sunfish are hardy fish and can adapt to a wide range of water conditions. However, they prefer slightly warmer water and will do best in an aquarium that is kept between 70 and 80 degrees Fahrenheit.

They are also not very fussy when it comes to water hardness and can tolerate anything from soft to hard water. However, they prefer water that is on the softer side.

The ideal pH range for green sunfish is 6.5 to 7.5.

  • Water Temperature: 70-80 degrees Fahrenheit
  • pH Levels: 6.5-7.5
  • Water Hardness: Soft to hard
  • Alkalinity Levels: Not picky

What To Put In Their Tank

Green sunfish are a species of fish that are native to North America. They’re a popular choice for aquariums because of their vibrant colors and active personalities.

When it comes to setting up their tank, you’ll want to start with a good quality gravel. This will serve as the foundation for the rest of the decorations.

From there, you can add in some plants, rocks, and driftwood. Be sure to choose items that are safe for aquariums and won’t affect the water quality.

As for the plants, we recommend going with something that can tolerate a bit of abuse. Green sunfish are known to uproot things from time to time, so something like Hornwort or Java Moss would be a good choice.

As for the rocks, you’ll want to avoid anything too sharp or jagged. These fish are known to rub against surfaces, so you don’t want anything that could cut them.

Finally, driftwood is always a nice addition to any freshwater tank. It not only looks good, but it provides a place for these fish to hide and feel secure.

Common Diseases

The Green sunfish is a hardy fish that doesn’t usually fall ill. However, there are a few diseases that you should be aware of.

The most common disease that these fish experience is ich. This is a very common freshwater parasite that can affect any fish, no matter how big or small.

The most obvious symptom of ich is the presence of white spots on the body of your fish. If you notice this, it’s important to take action immediately.

The other disease that you might see in your Green sunfish is fin rot. This is an infection that usually starts in the fins and spreads to the rest of the body if left untreated.

The most obvious symptom of fin rot is, as you might have guessed, the deterioration of the fins. They will become ragged and may even fall off entirely if the infection is severe enough.

If you notice either of these diseases in your fish, it’s important to take action immediately. Consult your vet and begin treatment as soon as possible. The sooner you act, the better the chance is that your fish will recover.

Behavior & Temperament

The green sunfish is a very peaceful fish that can get along with most other tank mates. They are not an aggressive fish, and will usually only attack if they feel threatened.

Green sunfish are a schooling fish, so they do best when they are kept in groups. They are also a very active fish, and will often swim near the surface of the tank.

Green sunfish are a very hardy fish, and can tolerate a wide range of water conditions. They are also very easy to care for, and are a good choice for beginners.

Tank Mates

The green sunfish is a peaceful and docile fish that does well in community tanks. They can be kept with a wide variety of different fish species as long as the tank is large enough.

Green sunfish are also relatively easy to care for which makes them a good choice for beginner aquarists.

Some good tank mates for green sunfish include:

  • Guppies
  • Platies
  • Swordtails
  • Mollies
  • Endler’s Livebearers
  • Neon Tetras
  • Cherry Barbs


Green sunfish are fairly easy to breed in captivity. They don’t have any specific requirements and will readily spawn in most tanks.

To increase your chances of success, start by adding plenty of hiding places. These fish like to have a lot of places to hide. That way, they feel safe and secure.

Next, add some live plants. Green sunfish will often lay their eggs on the plants.

You don’t need to make any changes to the water. Just keep it clean and at the right temperature.

When ready, add a group of Green sunfish to the tank. The ratio of males to females doesn’t matter too much. Just make sure there are more fish than you want to end up with.

These fish are opportunistic breeders and will spawn whenever the conditions are right. You may see the males chasing the females around or guarding a certain area of the tank.

Once the eggs are laid, the male will guard them. He will also fan them with his fins to keep them clean and oxygenated.

The eggs will hatch in about a week. At that point, you can remove the adults and start feeding the fry live foods.


The Green Sunfish is an excellent fish for the beginner aquarist. They’re very easy to take care of and are very adaptable to different conditions.

They’re also a very peaceful fish, so they’ll do well in a community tank.

Overall, we think the Green Sunfish is a great choice for anyone looking for an easy-to-care-for fish.