Full Grown Angelfish – How Fast Do They Grow?

One characteristic that attracts hobbyists to freshwater angelfish is their size, with specimens reaching their full potential at 1.0 to 1.5 years of age.

Several factors will influence the growth rate and body size of this native of the Amazonian River basin in South America, so you must know what they are to provide your adult angelfish with the best aquarium environment.

We have spent years breeding and keeping a variety of angelfish species. During that time, we have learned what can influence growth rate, and we want to pass this knowledge on to you. Things we will cover in this article include:

  • How big they get
  • Their growth rate
  • Tank size
  • Growing tips
  • Answers to common questions

How Big Do Angelfish Grow To?

Freshwater angelfish often reach at least four inches in length and six inches in height. Fully grown specimens can reach larger sizes under the right conditions, but the 4×6-inch measurement is a good average found throughout the hobby.

Small angelfish not fully grown

These numbers can be misleading as diet, cramped space, and less-than-ideal water conditions prevent these fish from reaching their full size. For example, if you feed your pets properly, the average size can jump from 4×6 inches to a full size adult that is six inches long and eight inches tall.

A fish’s species will also influence how big they get. There are three recognized species of freshwater angelfish, including Pterophyllum scalare (common angelfish), Pterophyllum altum (altum angelfish), and Pterophyllum leopoldi (Dumeril’s angelfish). While the common angelfish can reach the 6×8 inch sizes described above, the altum angelfish can get up to seven inches long and ten or more inches in total height!

While sex-related size does not provide breeders and keepers hard and fast rules, we have observed over the years that female angelfish tend to be smaller than their male counterparts. You may find sources claiming that female angelfish are up to 33% smaller than males, but we have not witnessed that big of a difference ourselves.

How big is a full grown angelfish in the wild?

The home waters in South America offer ideal conditions for these cichlids to mature to maximum sizes, so it should be no surprise that wild fish can outgrow their captive-bred cousins. Full grown common angelfish will reach six inches in length and eight inches in height without difficulty. The largest freshwater species, Pterophyllum altum, will get over one foot tall (see the wild-caught fish at 1:49 here), and we have read about unverified reports of wild specimens reaching 19.6 inches in height.

If you can match their native water conditions, your adult angelfish should be able to reach the same size they would in the wild. Remember that anomalies among angelfish will push the size envelope or fall short of it during your fishkeeping journey.

How Fast Do Angelfish Grow?

Freshwater angelfish become fully grown by 1.0 to 1.5 years after they hatch. Unless you breed them yourself, you will likely obtain specimens at least at the juvenile stage, if not full size, through breeders or shops. If you have a breeding pair of adult angelfish, you can observe the developmental cycle these South American cichlids grow through.

Life for your angelfish starts as an egg about 1.46 mm in size. Angelfish eggs hatch about 72 hours post fertilization. The male and female angelfish will protect these wigglers until they become free swimmers, and the fish will reach 15 mm in length by 23 days post-fertilization.

From there, angelfish become juveniles and rapidly grow until six months. Your angelfish will be between four to five inches long at this age and can reach sexual maturity. Growth rates begin to slow at this stage, but your angelfish will continue to increase in length and height for another six months to one year before becoming a full grown specimen.

What Size Tank Do I Need for Fully Grown Angelfish?

We recommend 30-gallons as a minimum tank size for a pair of freshwater angelfish. Avoid anything smaller than this size tank (you could keep a single specimen in a 20-gallon tank, but these shoaling fish do best with at least a pair). Check out our guide to best tank for angelfish.

These natives of South America have more height than length and will respond well if you place them in aquariums referred to as high or tall within the trade. If you want to raise the largest adult angelfish possible, step up to a 55-gallon.

Contrary to what you may read online, aquarium size does not limit growth rates for angelfish. Factors like oxygen support, mobility, territory, and pollution levels necessitate a tank with more water volume.

An often-used calculation in the hobby that offers a good starting point is one inch of fish per gallon of water. If you are unsure about how many fish to place in a large aquarium, follow the advice of breeders and vets by understocking a tank and adding only a couple of fish at a time. That helps avoid many problems that can cause stress for your pets.

Tips for the Best Angelfish Growth

Diet and Feeding

The top thing you can do to promote healthy growth for your freshwater angelfish is to provide a nutritious diet. Angelfish diets in the waters of South America tend to focus on various invertebrates like small crustaceans, insects, larvae, and worms.

These fish are omnivores, however, meaning they eat animals and plants. Feed your pets high-quality flakes and pellets, with an emphasis on animal protein but not ignoring plant food sources. A poor diet can create conditions like stunted growth in your angelfish.

The number of times you feed your fish daily can also affect growth rates, especially with developing free swimmers and juveniles. Consider offering food to your juveniles three or four times daily and your adults twice during the same period. These higher feeding rates allow your fish to maintain nutrient levels and maximize the energy for continued growth.

Reduce Stress

Outside of nutrition, the next best thing you can do to improve the growth of your freshwater angelfish is to limit stress factors that can develop into sickness. Males will need space to establish territory, and both male and female angelfish will benefit from having a place to withdraw and hide if needed.

Water needs to be clean, so filtration and water changes are mandatory. Perform weekly water changes with up to 25% replacement, but avoid changing more than that to limit angelfish aggression. You can provide filtration that cycles the entire water column more than once per hour, but ensure it does not create strong currents that your adult angelfish will not like.

Proper water parameters are also necessary to promote the best growth rate for your angelfish. A temperature range between 75 and 84 degrees Fahrenheit is adequate for captive-bred angelfish, but you might want to stay closer to the 80-84 degree range if you plan on breeding. A pH between 6.5 and 7.5 is necessary, and the water should have a dH between 5 and 12.

Finally, do not overcrowd your aquarium or stock it with incompatible tank mates. Following these rules will reduce stress levels and help your angelfish reach full size.

Growing Happy and Healthy Angelfish

If given the right conditions, your pets can reach a fully grown size of at least four inches long and six inches high. Several factors, including species, can increase that range.

Angelfish can take up to 1.5 years to reach maximum size. Like most animals, angelfish tend to grow the most at the start. They will achieve four or five inches in six months and take up to a year to finish their path to adult angelfish. Use at least a 30-gallon tank for a pair of fish, and remember, diet and stress affect growth rates the most!

We want you to grow in the hobby like your fish, so leave a comment or question to continue the discussion!


How big do angelfish get?

Your angelfish will grow to be at least four inches long and six inches tall. Most common angelfish can reach six inches by eight inches, while the altum species will get about seven inches long and at least nine inches tall.

Will angelfish grow in a small tank?

They can, but some factors make this unhealthy. The aquarium needs enough water to supply oxygen, provide stable water conditions, and offer mobility and a place to stake territory. We suggest a minimum of 30 gallons for a pair of freshwater angelfish.

How long does it take for an angelfish to grow?

You can expect your pets to reach their full size by 1.0 to 1.5 years after they hatch. Unless you breed adult angelfish and raise the young, the specimens you purchase will likely be juveniles with only a few months left of growing. If you buy large angelfish, they are likely fully grown already.

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