introducing new angelfish

How To Introduce New Angelfish

Introducing a new angelfish to an aquarium can be a difficult process. These fish are known to be slightly aggressive. They themselves can get picked on if housed with incompatible tank mates. Fish may refuse to eat, die from shock, or seclude themselves from the others. To properly introduce new angelfish to the tank, you need to be careful.

When you bring an angelfish home, start by placing it in a quarantine tank. Float the bag in the tank for 20 minutes, then open the bag and add the tank water to it, one cup at a time. Space this over 30 minutes until it’s full, and then release the fish. You can prepare the main tank for the fish by dimming the lights and feeding all the fish. If your angels are territorial, rearrange their decorations to disrupt boundaries.

You should always double-check the main tank’s water parameters. After that, make sure that any fish in the tank are already suitable tank mates for angelfish. Certain fish, like Oscars, will attack angelfish. Likewise, angels will eat small fish like guppies.

Introducing New Angelfish

Introducing new angelfish to a populated tank should be approached with caution. Angelfish are known for being feisty and bullying other fish. Adding new angelfish to an existing angelfish group triggers issues, since:

  • The existing fish have a social hierarchy, which the new fish doesn’t yet belong in
  • There are already territories and boundaries in place, leaving no room for a new fish
  • Mates are already chosen, leaving the new fish as the odd-one-out
  • Baby fish and fry could be hatching and growing, making the parents aggressive toward newcomers

This can result in fights, leading to injury and death. Angelfish react to stimuli in the environment and adjust their behavior, according to Behaviour Brill. Adding new fish to the tank will draw out new behaviors.

Dominant fish can be more aggressive, picking on the new member. Shier fish, or new fish, may hide for up to a week until they feel comfortable in their new home.

Adding New Fish To An Established Tank

Avoiding fights and bullying means taking a few steps before adding the fish. Here’s the best way to proceed.

Check For Fry

Before anything else, ensure that no current angelfish are spawning or caring for fry. During this time, the parent fish will be more territorial and aggressive to others.

Break Up Territories

You can also move a few items around in the tank to disrupt established territories. This doesn’t always work, but it can distract the fish. It’s also important to make sure there are shelters for new fish to retreat to as they acclimate.

Add New Decorations

Adding plants is always a good idea, especially for angelfish. These creatures enjoy plant life to hide behind and nibble on. Not only will this give a new angelfish a new hiding place. It gives the existing angelfish a curious new object to investigate. This will take their attention off the newcomer.

adding angelfish to a community tank

Quarantine New Angelfish

Before adding new fish to a tank with an existing population, it’s always a good idea to quarantine them. That’s true not just for angelfish.

It’s okay for a quarantine tank to be smaller than the ideal tank size for the fish. That’s because the fish will only be living here for 2-3 weeks. It shouldn’t be excessively small, but a few gallons less than ideal will be fine. You can use the tank you saw at the aquarium shop as a reference.

A quarantine tank can be fully or partially filled using water from your existing tank. This has the benefit of introducing established bacteria into the tank. However, this tank still should be allowed to cycle for 2 weeks before adding any fish. You will need:

  • A heater
  • Light
  • Filter
  • Possibly an air pump, if there isn’t enough surface agitation
  • Sponge filters are a great 2-in-1 solution.

You can include an ornament or fake plant for the fish to hide behind for comfort’s sake. This will help minimize stress.

Introduce Slowly

After quarantine, avoid placing the fish directly in the tank. If there are conflicts, this could physically damage the new fish right away.

Instead, place the newcomer in a fry basket or a clear container. This can then be placed in the tank. The new and old fish can now investigate each other without the risk of harm.

Feed The Existing Fish And Dim The Lights

After 15-20 minutes, feed all of the fish as usual. You should then dim the lights or turn them off completely. Gently release the new fish into the tank and watch for any worrisome behavior. Should any overly aggressive behavior arise and not subside within 30 minutes, consider separating the fish for safety’s sake.

Just note that the fish already need to be acclimated to the water temperature and chemistry in the new tank. This minimizes the potential for the fish to go into shock. Not allowing a fish to gradually acclimate to water can cause shock, which may lead to death.

Give The Fish Time

If there is conflict and you’ve separated the fish, then wait 30 minutes to 1 hour and try again. Leave the new fish in the fry basket or container as long as you can.

If mild aggression happens, you can wait for the fish to calm down. If the aggression gets heavy-handed, you’ll see this when fish end up running into walls or decorations. Remove the new fish and wait again.

If no conflict arises, leave the new fish here for one day. You can then release it into the tank, if no fights break out. Keep an eye on the fish in the coming hours. The existing fish may be distracted enough by the new decorations and lighting, and be well-fed, so they don’t bother the newcomer.

Can I Skip Quarantining New Fish?

Quarantining new fish is very necessary. While you can technically skip this step, it may result in the new fish getting sick or infecting your tank with an illness. You won’t know this until it’s too late. It’s better not to risk it.

Wild-caught and farmed fish are exposed to a myriad of different organisms before you bring them home. For example, The Journal of Fish Diseases found that a single freshwater angelfish breeder population had a widespread outbreak of iridovirus. That resulted in many deaths.

Some aquarium shops will quarantine new arrivals before putting them up for sale. However, this isn’t always the case. Quarantining fish allows any illnesses, infections, or parasites to make themselves known before they can contaminate the main tank.

It is much easier to treat such problems in a small quarantine tank than a large one. Quarantining preserves the health of your current fish, and protects weaker fish from being harassed.

As a plus, quarantining allows the new angelfish to partially acclimate to its new environment with minimal stress. That’s especially true if you included water from your existing tank.

Introducing Smaller Angelfish

Is it a smart idea to group small angelfish with big angelfish? Or will it merely result in a gory catastrophe in your beautiful aquarium?

Angelfish tend to be more aggressive towards other adult angelfish. Smaller angelfish may be lightly harassed in the start, but they tend to be ignored shortly thereafter. That is, unless paired couples are spawning. Such times will see heightened levels of aggression and territorial behavior.

Angelfish are of the cichlid family, so will exhibit predatory behavior when housed with smaller fish. They are not known for being cannibals unless highly stressed or very hungry. Juvenile angelfish may be lightly bullied, but this should fade not long after the fish are introduced.

Small Angelfish With Big Angelfish

Introducing smaller angelfish to a tank is best done in small groups of 3 or more. It limits the amount of harassment bigger fish will exhibit. After all, they can’t single a lone fish out. Animal Cognition found that juvenile fish would shoal with similar fish in a new environment.

As such, the fish will initially shoal together, before eventually joining the existing shoal of larger angelfish.

Follow the same procedure outlined above for introducing new smaller angelfish to a tank. Female angelfish tend to be accepted to the school quicker than males. If you’re dealing with a very aggressive tank, consider only working with females.

Adding Angelfish To A Community Tank  

In certain cases, angelfish make a great addition to community tanks. Take careful note of ‘in certain cases.’ Angelfish are predatory fish that live on omnivorous diets. In captivity, they have no need to hunt for food. Nonetheless, housing angelfish with small fish, like small tetra or guppies, will still trigger hunting instincts.

You must always be careful when curating community tanks, especially with diverse species.  Larger fish, like Oscars and African Cichlids, can turn on and attack angelfish. Certain fish species can also be fin nippers.

They will only be compatible in larger tanks that allow for personal space. Given this, many angelfish keepers will create angelfish-only tanks. There are many compatible tank mates for angelfish, including:

  • Corydora catfish
  • Silver dollars
  • Pleco catfish
  • Mollies
  • Dwarf gouramis
  • Swordtails
  • Rainbowfish
  • Large tetra species
  • Blue rams

When populating a community tank, it’s wise to introduce new fish by adding them all at the same time. This prevents any fish from staking out territory and becoming aggressive.

Angelfish Community Tank Setup

Community tanks are usually more work, but certainly worth the effort. Finding the balance between the needs of each individual species can be tricky. Thankfully, there is plenty of information available for angelfish community tanks.

Choose The Right Size

Ensure that your tank is large enough for the number of fish in it. A standard-sized tank for a pair of angelfish is 30-40 gallons. After all, these fish need a lot of space. If you want to keep a small school of angelfish, upgrade to a 55 gallon or larger tank.

The tank size and setup will also depend on what other fish you want to keep in the tank.

  • Catfish and bottom feeders will happily coexist in a 30-55 gallon tank.
  • Fish that dwell at the mid-level or near the surface, like gouramis, will need a bigger tank.
  • If other fish dwell at the same level as angelfish and are similar in size, add another 10 gallons to your minimum tank size.
  • For a school of 3-5 angelfish and 6-7 additional tank mates, a 55-gallon tank will usually suffice.

Always ensure that there are plenty of plants and ornaments in such a tank that act as buffers for fish seeking shelter.

Minimum Number Of Angelfish

In big enough tanks, angelfish do extremely well in large groups. You’ll see natural schooling behavior arise in groups of 5 or more. For many, this is desirable, as angelfish weave and glide through the water gracefully. Shoaling behavior makes these movements even more pronounced.

Angelfish can live in big groups, so long as the tank is large enough to accommodate them. Keep in mind that the more crowded the tank, the more frequently maintenance is needed. A group of 3-5 is ideal.

small angelfish with big angelfish

Can Two Male Angelfish Live Together?

Male angelfish can live together. However, this greatly depends on the size of the tank. If the two males feel crowded, they may become highly defensive of their territory. This will encourage them to fight and potentially kill other males. To make sure no serious fighting occurs, you can always get a 55-gallon tank for the pair.

Angelfish usually get aggressive toward one another when spawning or protecting fry. A single-sex angelfish population may be more ideal for some people. You won’t have mating to worry about, which will cause fewer conflicts.

With that said, angelfish are tricky to sex before they are fully grown. If you have two males and one female, this may cause more fighting. That makes it wise to keep 2 angelfish at a time, or larger groups of 4-5. This will help balance out the sexes.

If you find you have a tank that’s predominantly male, with very few females, consider using distractions. You could invest in a larger tank, with more decorations. This will give the fish better things to pay attention to, and plenty of space to carve out their own territory.

Are Angelfish Hardy?

Angelfish are considered hardier fish. They can tolerate a wide variety of tank parameters. However, these parameters must still exist within an acceptable range of their ideal tank setup.

Likewise, angelfish still need careful and consistent care. You should never suddenly introduce new angelfish to a tank. Hardy as they are, angelfish are susceptible to shock if simply dumped from the store bag into the tank. This is why an acclimation process is so important. The fish needs to adjust to a difference in:

  • Temperature
  • Water hardness
  • Acidity

When kept in perfect conditions and fed a proper diet, angelfish can live up to 10 years. If you apply care and attention for just a few weeks in the beginning, you can have pets for a decade.

New Angelfish Stays In Corner

You may notice that your new angelfish seem shy. It may hide in the corner or isolate itself from other fish. Although they’re not overly energetic, angelfish aren’t prone to hiding without a cause. After a settling-in period, most angelfish will happily move throughout the tank. As such, you should observe the fish.

  • Does it make any attempt to emerge from hiding?
  • Are other fish harassing it?
  • Is it refusing to eat?
  • Does it have any injuries or obvious signs of infection or the like?

If the answer is “yes” to these questions, record the symptoms and seek out the right treatment. If the fish is being bullied, the tank may be over-populated.

Why Is My New Angelfish Hiding?

Angelfish hide when feeling unwell, and not only due to illness or disease.

Bad Water Conditions

Even though angelfish are hardy, incorrect tank parameters will still impact their well-being. For example, too-cold water will slow their metabolism and system down. This can make them sluggish and constipated, inspiring the angelfish to hide. Check the parameters of the tank.

  • Is it set to the correct temperature, pH, and hardness?
  • Is the filter’s output too strong?

Make corrections and you should see the angelfish becoming more active.  

Too Much Light

Angelfish can also hide when stressed, and an over-exposure to light can cause this. Only keep the tank’s light on for 6-8 hours each day.

Nowhere To Properly Hide

An angelfish may also hide in the corner when there aren’t enough plants or objects in the tank for it to shelter behind.  Remember that a new fish is going through a very stressful time. Try to accommodate it by giving it a place to rest.

As long as you introduce new angelfish slowly and carefully, they should join the group without issue.