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American Flagfish Care, Breeding & Tank Mates Guide

American Flagfish Care, Breeding & Tank Mates Guide

The American Flagfish (Cyprindon Floridae) is not among the typical choices in an aquarium. This is odd because it has unique colors and with little imagination, you can see a resemblance of the American flag. If you have not yet discovered that, it is native to Florida.

This species fits perfectly in cold-water community tanks but their most preferred environment is heavily planted aquariums. This is because they are vicious algae eaters.

People often use them as an alternative to shrimps. With this said, the American Flagfish will not only bring a nice touch to your colorful landscape, but it will destroy the unwanted algae.

What do you need to know about the flagfish to ensure its well-being in your tank? The most obvious answer is everything. Read below to find out how to take care of your American Flagfish in detail.

How does the perfect tank for an American Flagfish look like?

To begin with, let’s discuss the perfect environment for this species. The key with this fish is to make your aquarium as natural as possible. To the very least, you should have a lot of plants and hiding spots.

Such are rocks and driftwoods. The Flagfish is relatively small. In an aquarium, you can expect it to grow to around 2 inches or 5.0 – 5.5 cm.

Fish of this size feel the safest in large community tanks when they have a variety of hiding options. Of course, an over-planted aquarium is not a good idea as well, simply because this species is used to lakes and ponds that have a lot of open swimming space. Make sure you have different decorations but enough space for swimming.

The minimal tank size for an American Flagfish is not less than 10 gallons. Usually, they would be kept in pairs, therefore consider at least 20 gallons as a start. However, This species thrives when it is in a group of more than five. In such cases, the tank should be relatively larger.

Although we mentioned that they are great for community tanks, there are certain rules when it comes to tank mates. The Flagfish is quite territorial and it could act relatively aggressive.

The most suitable tank mates are fast swimming fish. As long as you keep the size requirements, there will be no signs of aggression as the fish will have enough space for its own territory.

See the table below to find out all tank and water requirements for the American Flagfish.

Minimum Tank Size 10 gallons
Temperature 66F – 85F (19C – 29C)
pH 6.5 – 8.0
Hardness Medium hard and alkaline
Strata Bottom or middle


This species is omnivorous. Our tip on the diet is to use a variety of high-quality foods. This will bring out their beautiful natural coloration. They will eat practically everything but the key is to bring diversity into their diet.

To begin with, the American Flagfish will actually eat almost everything that it can find in the tank. Starting with the different types of algae growing on plants and rocks, to the actual plants. Besides that, a good day to day food are algae pellets/tablets, green flake food, vegetables.

In addition, live and frozen food will be happily accepted. Such are brine shrimp, tubifex, blackworms, daphnia. If you decide to include any of those favorites to the diet, make sure you use them once or twice a week. These foods are packed with protein. Too much of it, however, is not safe.

Vegetables are a good addition to the diet as well. The most favored ones are zucchini, peas, and cucumber. If you want to add extra vitamins to the diet, try lettuce and spinach.

Sexing and Breeding

It may surprise you, but the American Flagfish is extremely easy to breed. You actually do not have to do anything to start the process. This species will breed randomly in larger tanks. Usually, this would happen in winter or spring.

To begin with, you need to know you actually have females in the tank. Otherwise, there will be no point in watching out for pregnancy. With this species, genders are easy to differentiate.

Females tend to be larger and have a more rounded belly. In addition, you can look for a blot on the back. Males do not have those. Finally, males have a larger variety of colors while females have a lot more yellow in their coloration.

Naturally, American Flagfish will scatter their eggs all around the tank. As it is hard to protect the newborns in the large community tank, make sure you have an additional breeding aquarium. It can be smaller but make sure that the temperature is higher than in the original tank.

In the breeding tank, there should be enough plants as well. This time, not for food but for hiding spots for the female. Males from this species can become overly enthusiastic and demanding during the spawning process.

The female will need a place to hide and rest if she needs it. In addition, they are known to lay their eggs in floating roots as well. In this case, remove the parents as soon as the eggs have been disposed of. Naturally, fish eat their eggs or newborns.

The other most common disposition spot is a hole in the substrate or gravel. In this case, the male will serve as a guard and protect the eggs until they hatch.

As soon as the eggs have been laid, you can return the female to the community tank. As for the male, wait until the eggs are hatched and the newborns start swimming freely. This period is usually 7-10 days.

Another factor for the survival of the fry is aquarium depth and filtration. American Flagfish are not used to currents and fast-moving waters.

After all, their natural habitats are lakes and ponds. Keeping the current as minimal as possible is very important. For the newborns it is crucial. If you do not use a soft filtration method, they could possibly get harmed.

Furthermore, the breeding aquarium should be shallow. It is hard for newborns to reach the surface when the tank is deep. It is crucial for them to reach it, otherwise, they will most certainly die.

How to bring out their best natural coloration

As mentioned above, a healthy diet will help. Besides that, there are a few tricks with the aquarium setting that will bring out more colors from all your fish. It all starts with contrast. In order to get the colors to shine, think about buying darker substrates and background. In addition, LED lighting is another great way to enhance coloration.

Suitable Community for an American Flagfish

As already mentioned, American Flagfish can get excited and show signs of aggression towards slower fish. A Betta, for example, is a bad choice for a companion. It might get its fins nipped. You can try Danios, Tetras, Swordtails. As long as you have a school of fish, there shouldn’t be any problems.

If, however, you are really keen on a slow-swimming species of fish and want to keep them together, consider buying a larger tank and providing a lot of hiding spots for fish to rest.

Additional Information

In this section, we will provide you with the most suitable products for American Flagfish that were discussed prior. All products are available on Amazon at the best current prices.

OMEGA One Freeze Dried Brine Shrimp

This is one of the most preferred Brine Shrimp products in the world. It is not only the highest quality of food but it is suitable for both freshwater and marine fish. For us, it is important that it is perfect for American Flagfish. It is packed with huge amounts of protein and vitamins. Just remember that this shouldn’t be fed more than twice per week. Overfeeding with protein might lead to significant health issues.

Why choose this food?

  • As nutritious as live food
  • Free of parasites and bacteria
  • High amounts of protein
  • Less waste

Tetra TetraVeggie Algae Wafers

From personal experience with American Flagfish, this is the most suitable algae wafer on the market. Even if your tank is cleaned entirely of algae, this species needs to receive it daily. This product is made from some of the healthiest foods for Flagfish – zucchini, algae, fibers. In addition, we already mentioned how important a balanced diet is to bring out the natural coloration.

Why choose this daily food?

  • Algae Enriched
  • Made with zucchini, a favorite of the American Flagfish
  • Nutritionally balanced

Fluval C Power Filter

We mentioned above that the filter is very important for both grown and newborn American Flagfish. They are not used to quick waters and currents. The Fluval C Power Filter is an amazing choice for this species as it has 5 stages of filtration and the flow is absolutely adjustable. In addition, it is available in three sizes, therefore you do not need to overspend if you have a smaller tank.

The smallest option is suitable for tanks up to 30 gallons, while the larger versions can filter respectively up to 50 and 70 gallons. In addition, it is highly technological and has some special features that will be listed below.

Why choose this filter?

  • 5 stages of filtration
  • Cleaning indicator – signals when you need to rinse the polyfoam
  • Easy maintenance
  • Adjustable flow

Additional Questions

Is the American Flagfish aggressive?

Naturally, this species is territorial but is rarely aggressive towards other fish. It is a possibility if the tank is too small. If you plan on having a couple, definitely go for a tank with a minimum of 20 gallons.

In addition, if you want to have slow swimming fish with the Flagfish, consider creating a lot of hiding spots. The American Flagfish is rarely aggressive, but it could nip the fins of slower fish. The safest option is to have a lot of space and quicker fish like Danios or Tetras.

Does American Flagfish need a heater?

This species usually lives in cold waters. Although it will thrive in waters of all temperatures and the range is wide, it is advisable that the water is below 85F (29C). Naturally, you will hardly ever need a heater for your aquarium. Room temperature will be suitable for this species.

Will American Flagfish eat their eggs?

Naturally, fish tend to eat their eggs. The case is the same with this species, although it all depends on the personality of the fish. We mentioned above that eggs are usually laid in holes in the gravel or in floating roots.

If the eggs are in a hole, the male will actually protect them in most cases. I myself have witnessed both but in the majority of situations, the male will actually not eat the eggs.

Your safest option is to move the eggs to a secondary tank. In fact, you can separate the two Flagfish during the spawning period, but you have to remove the female when the eggs have been disposed of. If the male wants to watch over them, you can keep him there. If he shows signs of aggression and starts eating the eggs, move him to the community tank as well.

How to look after American Flagfish newborns?

Just like any other species, the fry is extremely vulnerable and require attention. As mentioned, the breeding aquarium should be shallow as the newborns need to reach the surface as quick as possible. This is key to their survival and I am speaking from personal experience.

As soon as the fry are hatched, they can be fed with microworms and infusoria. Although they look small and fragile at first, this species grows literally by the day.

At first, they will most likely stay at the bottom of the tank as they are not yet familiar with swimming. As soon as they learn and begin to move, you can switch to more serious foods like the baby brine shrimp.