Can You Keep Angelfish In A 5-Gallon Tank? (Practical Tips)

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Angelfish are pretty common these days, especially due to their astonishing look. However, even though they may seem simple, angelfish are pretty demanding when it comes to space.

Can you keep angelfish in 5 gallons? Would that tank size be too small for angelfish? And if so, what’s the minimum tank size you can use?

In this article, I’ll discuss all these questions and many more, ensuring you leave with all the information you need. Let’s get started.

Can I Have an Angelfish in a 5-Gallon Tank?

No, you cannot keep an angelfish in a 5-gallon tank. It’s not suitable for the long-term health and well-being of the fish.

  • Size Requirements: Angelfish can grow up to 6 inches tall and 8 inches long, making a 5-gallon tank far too small for an adult fish.
  • Behavioral Needs: Angelfish are active swimmers and require space to roam, and a small tank can cause stress and behavioral issues.
  • Water Quality: In smaller tanks, water parameters can change rapidly, leading to potential health issues. Angelfish require stable conditions.
  • Territorial Concerns: Angelfish can be territorial. In a small space, this behavior can be exacerbated, leading to increased stress.
  • Life Expectancy: With proper care and space, angelfish can live up to 10 years. A cramped environment can significantly reduce their lifespan.

Also Read: Angelfish Tank Size

What’s the Minimum Tank Size for Angelfish?

The minimum tank size for a single angelfish is 20 gallons. However, if you’re considering keeping a pair or a small group, a 55-gallon tank or larger is more appropriate.

  • Growth Potential: Angelfish can grow up to 6 inches in length and 8 inches in height, so they need ample space to grow and move comfortably.
  • Swimming Space: These fish are not only tall but also active swimmers; a larger tank ensures they have the horizontal space they need.
  • Water Stability: Larger tanks provide a more stable environment, helping maintain consistent water parameters which angelfish thrive in.
  • Group Dynamics: If you’re considering multiple angelfish, remember they can be territorial; a larger tank minimizes aggression by offering more territories.

Also Read: Can Angelfish Live In A 10-Gallon Tank?

How to Calculate the Appropriate Tank Size for an Angelfish

Here’s a method for calculating the smallest tank size suitable for an angelfish, in line with the one-inch-per-gallon principle:

  • Determine the adult size of an angelfish: up to 6 inches.
  • Using the 1 inch per gallon rule: 6-inch angelfish = 6 gallons.
  • Angelfish are tall and laterally compressed, requiring a tank with adequate height. This isn’t exactly quantifiable by the 1 inch per gallon rule, but it’s significant.
  • Angelfish are active swimmers and need extra space for movement: additional gallons are added for this reason.
  • Accounting for the aforementioned factors, while 6 gallons could technically house an angelfish, it would be quite restrictive.
  • Considering their height, active nature, and space for growth and comfort, the size is typically rounded up in recommendations.
  • Hence, many experienced aquarists, taking into account the above factors, generally agree on a minimum of 20 gallons for a single angelfish to provide a suitable environment.

Tips for Keeping an Angelfish in a 5-Gallon Tank

I must start by noting that keeping an angelfish in a 5-gallon tank is not recommended for the health and well-being of the fish.

However, if you find yourself in a temporary situation requiring such a setup, here are some crucial tips to follow:

  • Temporary Housing Only: This setup should be seen as a short-term solution, perhaps during emergencies, and not a permanent home.
  • Frequent Water Changes: Small tanks accumulate waste rapidly; ensure you change at least 50% of the water every 2-3 days.
  • Limit Feeding: Overfeeding in small spaces leads to water quality issues; feed small amounts to prevent excess waste.
  • Avoid Overcrowding: A 5-gallon tank isn’t suitable for multiple fish with an angelfish; avoid adding any other tank mates.
  • Monitor Water Parameters: With limited water volume, conditions can fluctuate. Regularly check pH, ammonia, and nitrate levels.
  • Provide Hiding Spots: Even in a small tank, offer a place for the fish to retreat to, like a soft plant or a small cave.
  • Plan for Relocation: Always have a plan to move the angelfish to a larger, more suitable tank as soon as possible.

Can I Keep an Angelfish with Other Fish in a 5-Gallon Tank?

No, you cannot keep an angelfish with other fish in a 5-gallon tank. The space is already inadequate for a single angelfish, let alone with additional tank mates.

  • Space Limitations: An angelfish can grow up to 6 inches, making the tank space insufficient even for one, without adding other fish.
  • Territorial Behavior: Angelfish can be territorial; in such cramped quarters, this behavior could lead to aggression towards other tank inhabitants.
  • Water Quality Issues: The more inhabitants in a tank, the quicker waste accumulates. This can cause rapid degradation of water quality in a 5-gallon setup.
  • Compatibility Concerns: While there are smaller fish or creatures like shrimp and snails, a 5-gallon space doesn’t allow for proper species separation or the necessary environments for each.

Does the Gender of Angelfish Matter?

No, when considering a 5-gallon tank, the gender of angelfish doesn’t change the fact that the tank is unsuitable.

However, there are differences between male and female angelfish that an aquarist should be aware of.

  • Size and Physical Differences: Male angelfish might grow slightly larger and often have a more pointed dorsal and anal fin, while females can be rounder during breeding times.
  • Breeding Behavior: If a pair forms, they’ll need adequate space for breeding. Females lay eggs while males fertilize them, and both can become territorial during this period.
  • Territorial Dynamics: Males might display more territorial behavior, especially towards other males, but both genders can be territorial in limited spaces.

How Many Angelfish Should Be Housed Together?

Ideally, angelfish should be housed either singly, in pairs, or in larger groups of 5 or more. Keeping them in groups of 3 or 4 can result in the weakest being bullied.

  • Tank Size: For a pair of angelfish, a 30 to 55-gallon tank is recommended. Larger groups require even bigger tanks to provide ample space.
  • Group Advantages: Keeping angelfish in larger groups can disperse aggression, ensuring no single fish is consistently targeted.
  • Female-Male Ratio: If breeding isn’t the aim, a mix of genders is fine. However, for breeding, aim for a natural pairing or maintain a 2:1 female to male ratio to reduce aggression.
  • Avoid Odd Numbers: Keeping them in groups of 3 or 4 often results in one becoming a target. Larger groups help prevent this pecking order.

What’s Suitable for a 5-Gallon Tank?

A 5-gallon tank is suitable for a few small fish or invertebrates, but not larger species like angelfish.

It’s important to choose species that thrive in smaller environments for the health and well-being of the inhabitants.

  • Betta Fish: These are solitary fish that can comfortably live in a 5-gallon setup, though they prefer larger spaces if available.
  • Small Tetras: Think Ember or Neon tetras, but even then, keep the numbers low to avoid overcrowding.
  • Shrimps: Cherry or ghost shrimps can be perfect inhabitants, and you can keep a small group in this size tank.
  • Snails: Nerite or mystery snails are great choices, helping with algae control and adding some activity.
  • Dwarf Frogs: African dwarf frogs can be a unique choice, but ensure the water quality remains pristine.
  • Dwarf Rasboras: Species like the Chili or Phoenix Rasboras are small enough for such a setup but monitor their numbers.
  • Live Plants: Opt for smaller plants like Anubias nana or Java moss to provide shelter and improve water quality.
Cherry shrimp

Which Fish Aren’t Suited for 5 Gallons?

Many fish are unsuited for a 5-gallon tank, as it doesn’t provide the space or environment they need to thrive. It’s vital to prioritize the well-being of fish when choosing tank sizes.

  • Goldfish: Often a starter fish, they grow large and produce a lot of waste; a pond or large tank is ideal.
  • Guppies: Though small, they’re active and breed quickly, which can quickly lead to overcrowding in a 5-gallon setup.
  • Corydoras: These bottom-dwellers love to roam and are typically kept in groups, requiring a larger space.
  • Mollies: They’re active swimmers and breeders, requiring more space than a 5-gallon tank can offer.
  • Platies: Similar to mollies, they’re active and breed often, necessitating larger tanks for comfort.
  • Swordtails: Growing up to 4 inches and being active, they require more space for healthy living.
  • Plecos: Even the smaller species grow larger than what a 5-gallon can accommodate and they produce significant waste.


For those of you who are just skimming through, here’s a short summary:

  • Angelfish cannot be kept in a 5-gallon tank as it’s too small for their size and behavioral needs, and can cause stress and health issues.
  • The minimum tank size recommended for a single angelfish is 20 gallons, with a 55-gallon tank or larger being ideal for a pair or small group.
  • A 5-gallon tank can be used as temporary housing for angelfish, but frequent water changes and monitoring are crucial, and relocation plans should be in place.
  • Angelfish should not be housed with other fish in a 5-gallon tank due to space limitations and territorial behavior.
  • A 5-gallon tank is suitable for small species like betta fish, small tetras, shrimps, snails, and dwarf frogs, but not for angelfish, goldfish, guppies, and other larger species.