How Many Endlers Can You Keep In A Tank? {Will They Fight?}

Are you wondering how many Endlers you can keep in a 5, 10 or 20 gallon tank? Will they get aggressive or stressed if they are too many of them? In this article, we’ll discuss the topic of keeping a comfortable amount of endlers in your tank.

How Many Endlers Can You Keep In A Tank? 5 Gallon tanks can house 5-7 males without any room for breeding with females and their fry. A general rule of thumb is 1.5 Endlers per gallon of water. 

How Many Endlers Can You Keep Together?

Endlers are social and shoaling fish. They are quite active and the males have an insatiable desire to breed with females. Their populations grow rapidly in a healthy tank. We suggest getting a 20 gallon tank for them to move freely and breed comfortably.

You can keep a single male with other peaceful tankmates, but it’s best to allow endlers to shoal for comfort and lessen their stress when they feel threatened.

Here are some suggested numbers for keeping plenty of endlers together:

  • 5 Gallons: Up to 7 endlers
  • 10 Gallons: Up to 15 endlers
  • 20 Gallons: Up to 3o endlers
  • 29 Gallons: Up to 43 endlers
  • 55 Gallons: Up to 82 endlers

How Do Endlers Behave In Groups?

Endlers are active swimmers. They will explore the full length and depth of your tank. You might find them picking at algae or investigating any covered areas.

They are small in size, but fearless when they feel the safety in numbers. They may shoal will needed, but they are free to move around at their own will.

They will establish a pecking order and dominant males will pursue, chase and harass females constantly. Because of this, it’s best to keep many more females than males in larger groups.

Are Endlers Aggressive?

The chasing you see usually happens when males are trying to present themselves to females as being the most suitable mates. Males may flare the vibrancy of their colors by taking advantage of light, glare and reflections to look more presentable.

They are not aggressive to other tankmates, but they may try to eat any smaller marine life that are small enough to fit into their mouths. Males without females won’t fight much without a need to establish the right to breed with a female, but they may get slightly territorial.

Females also establish their own groups with the largest becoming the most dominant. She may pick on weaker females and get other females to support her cause. Aggression levels are quite low compared to many other aquarium fish.

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Can I Keep 3 Male Endlers Together?

Males are showpieces. They are bright and vibrant. Most people wish to keep males together, but end up with more females when they are breeding endlers. Female dominant tanks are better for keeping the peace and making sure the males do not harass them with their constant urge to mate.

If you would like to keep only a few of them, you can definitely keep 3-7 male endlers in a 5 gallon tank. Two alone may fight more often. 3-7 is a better number to increase the peace.

A 5 gallon tank is too small for breeding purposes. This is another reason why it’s better to not stock any females with a small group of males. There simply isn’t enough space for their fry.

Can Endlers Be Kept Alone?

Although there are cases of a single endler getting lonely, there isn’t enough evidence to suggest that you can’t keep one only. A beautiful male showpiece endler could be displayed in his own tank, but would prefer to shoal if he feels uncomfortable.

Maintain pristine waters, vary his diet and allow for enough cover to give him the chance to hide when he feels unsafe. You can also keep a single endler with other peaceful fish in your community tank.

How Many Babies Do Endlers Have?

A female endler can produce up to 25 fry. The usual number rests somewhere closer 15. Look for the gravid spot on females. It’s a dark area behind the belly of the female endler.

A male will do a little dance and be allowed to mate with her. The gestation period takes about 20-25 days.

The fry reaches maturity and females grow up to 1.8 inches or 4.5 centimeters in length. Males will stay smaller at about 1 inch or 2.5 centimeters. They will live about 1-2 years.

Can I Keep Endlers With Mollies?

Endlers and mollies tend to get along just fine in community tanks. There are cases of a single male endler thriving in a tank with mollies without any stress over territory or food. The following tankmates are suitable with endlers:

  • Mollies
  • Cardinal Tetra
  • Ember Tetra
  • Neon Tetra
  • Platies
  • Swordtails
  • Cory catfish
  • Honey gouramis
  • Harlequin Rasbora
  • Otocinclus catfish
  • Kuhli loach

Which Fish Should I Not Keep With Endlers?

Endlers are small and peaceful. They will occupy spaces in the entire tank unless they are bullied. At this point, they will retreat, hide, stop eating and possibly fall ill. Active tankmates that are aggressive or territorial should not be kept with endlers.

The following fish made our list for unsuitable tankmates:

  • Cichlids
  • Rainbow sharks
  • Killifish
  • Flowerhorn
  • Tiger Barbs
  • Bettas


Endlers breed often. Their numbers will spread rapidly in your tank and they will surely outgrow it if you are placing breeding pairs of males and females together.

Consider starting with a 20 gallon tank if you wish to expand your endler population. They are absolutely fine in very large numbers. 1.5 endlers to 1 gallon of water is the generally accepted rule of thumb.

If you wish to go smaller, keep 3-7 males alone in a 5 gallon tank. A single endler is not out of the question, but look for signs of loneliness or stress.


Thank you for stopping by at for all your informational needs concerning the fish you wish to keep in your aquarium. We have plenty of articles on a wide variety of marine life that may also pique your interest. See you again soon!

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.