How To Care For Danios: The Complete Guide


If you want a freshwater fish that’s good-looking, not too small, and with lots of personality, then the  Danio and its various species is a great fit. This fish is not shy at all and are very energetic. Plus, they’re very hardy.

Danios Got Variety!

The Danios is easily one of the most favorite fish in the tropical fishkeeping hobby. They can be found in any community tank as they are easy to keep.

Danios (Danio rerio), also called Zebrafish, are tropical freshwater fish from the family Cyprinidae. They come from the warm rivers of Bangladesh, Pakistan, Nepal, and India. They can also be found in Southeast Asia.

And while the Zebra Danio is the most popular species in the hobby, there are other types of Danios that are equally interesting and a delight in any aquarium.

SpecieDescriptionColor
Zebra Danio2.5 inches max length, lives up to 5 yearsSilver with horizontal blue stripes, males have additional gold stripes, red with blue stripes
Celestial Pearl Danio (Galaxy Rasbora, Chili Rasbora)Averages 1 inch in length, good for nano tanks, lives up to 5 yearsWhite-spotted blue-orange
Giant Danio4 inches max length, lives to 5 yearsStriped and dotted blue-orange or turquoise
Leopard Danio3 inches max length, lives to 4 yearsSpotted blue-silver-yellow or orange
Pearl Danio2.5 inches max length, peaceful, lives up to 5 yearsSilver and blue with orange
Glowlight Danio1.5 inches max length,Yellow and orange on a silver base
GloFish DanioGenetically modified to glowGreen, orange, yellow, purple, red
Longfin Danio2 inches max length, lives 4 to 5 yearsBlue-silver-purple, leopard-like
Kyathit Danio (Orange-finned Danio)Rare, with honeycomb or leopard pattern, can tolerate cold waterStriped with blue color, fins turn orange or red upon maturity
Cross-banded Danio (Cross-banded Rasbora)1.5 inches max length, peaceful, lives 3 to 5 yearsOrange on blue tiger-like stripes
White Cloud Mountain Minnow (Chinese Danio)2 inches max length, lives 5 or more years, can live in an unheated aquariumSilver with red fins
Rosy Dano (Purple Passion Danio)2 inches max length, lives up to 5 yearsSilvery-pink, purple-blue-silver, reddish silver
Zebra Danios
Zebra Danio

There are around 30 types and variations of the Danio and new ones are constantly being bred in tanks.

Are Danios Dangerous? Learn About Danio Behavior

Danios love to chase each other around. They are said to be tireless unless it’s nighttime It’s a great sight to see!

Danios are very active schooling fish so it’s not enough to keep just one or a pair. The best way to keep them is in a group of at least 6 of the same species. More is better in a good-sized tank.

Pearl Danios
Pearl Danio

But just like with most schools of fish, Danios will fight for hierarchy. A little show of dominance here and there is fine with some chasing, but no real damage should happen between fish.

Their high energy also makes them eager mates. So opt for more females than males to keep them occupied, like 3 females for every male. Otherwise, the restless males will stress out what females you have. And stressed-out fish can become sickly and problematic.

Giant Danios
Giant Danio

Danios also school with other species of Danios. For example, Zebrafish can go along with GloFish, Rosy Danios, and Blue Danios. They do this when their particular species is fewer than what they would like. They stick together especially if they feel threatened and stressed. If they don’t seem to be schooling, you can solve that issue as you get our tips from “This Is Why Your Zebra Danios Are Not Schooling!”.

It is this schooling nature that keeps them happy and active, but a lack in numbers will cause problems including stress and aggression. If you want to understand this better, we suggest you head on to “Zebra Danios Nipping Fins? What You Must Know” for more information.

Will Your Danio Survive? 7 Tank Conditions For Danio

The great thing about Danios is that they can survive in a wide range of parameters. Because of this, the Zebra Danio is often used for scientific research, as is the case when scientists created the very first GloFish.

Leopard Danio
Leopard Danio

Keeping Danios is easy. Here are their required parameters.

ParameterRange
Temperature65 to 78°F (18 to 25°C)
pH6.5 to 7.5
Ammonia0 ppm
Nitrite0 ppm
Nitrate< 40 ppm
Water hardness5 to 19 dGH
Tank size20 gallons minimum for a school of 6 Zebra Danios, 55 gallons for a school of 6 Giant Danios

Because they love to swim, choose a tank shape that’s long rather than tall for its size. And make sure you have the extra space if you plan to keep other types of fish. A bigger tank is also easier to maintain as the water doesn’t get dirty easily, but Danios are not known for producing a lot of waste anyway. This is what we talk about plus more on “Do Danios Produce A Lot Of Waste?”.

As you can tell by their speed, Danios are strong swimmers. That’s why a tank lid is necessary to keep them from jumping out. A dried-out Danio on the floor is a horrible sight, so read “Do Danios Really Jump Out Of Tanks?” for really good tips on tank lids and the Danio’s jumping behavior.

Glowlight Danio
Glowlight Danio

Hang-on back filters are the easiest and most common filters used in Danios tank setups. They’re more powerful than sponges but aren’t as expensive as canisters. They’re good enough to keep a community tank water clean as long as they’re regularly cleaned. Plus, they provide some flow which Danios love.

Normally, Danios would need a heater in their tank as they are used to tropical climates. However, there are exceptions for certain species and in specific conditions, as we prove in “Do Danios Really Need A Heater?”. Read up if you would like to try a heater-less setup.

With that knowledge, you can even put them in a pond or a nano tank. Check out “Can Zebra Danios Survive In A Pond? – 5 Reasons” for a different kind of outdoor fishkeeping adventure.

Having lots of live plants is very beneficial to Danios as they have places to hide, extra bio-filtration, and more oxygenation available to them. They especially love Java Ferns, Hornwort, Amazon Swords, Creeping Jenny, Java Moss, and Duckweed.

That also means you would need substrate to keep these plants in. You can choose anywhere from fine sand to small pebbles and they’ll be fine. These fish don’t require any special substrate.

Ornaments are great additions to a Danios tank. They add personality plus blockages to aggressive tank mates as well as resting spaces for the fish. There are no limitations except for sharp edges or too small holes that your fish might get caught in.

Tannins are not necessary but healthy and relaxing for Danios. Aside from the Indian Almond leaf, you can try driftwood as part of your design. Wrap edges with some Java Moss and marvel at your aquascape in a few months when the plants spread.

What Can You Feed Your Danios?

Danios aren’t hard to feed at all, but giving them a variety of foods keeps them healthy.

The Danios’ diet is omnivorous and can be made up of commercially prepared food such as flakes and pellets, as well as live and frozen foods like brine shrimp, bloodworms, and mosquito larvae (where allowed). Supplement these with some spirulina, algae, or cut-up vegetables from time to time (cucumber, zucchini, spinach).

Gorgeous Kyathit Danio
Kyathit Danio

Danios can even eat other types of food as we describe in “Is It OK For Zebra Danios To Eat Betta Food?” as their diet to other tropical fish is pretty similar (although Danios eat less protein).

Danios are insatiable eaters and will keep on munching as long as you keep putting in food. So put just enough food for them to finish in about a minute. Them slowing down without finishing means you’ve overfed them. To keep your water clean, remove uneaten food from the tank.

The zippy Danios like to graze and feed all the time as we write on “Are Zebra Danios Bottom Feeders?”. However, they generally stay in the middle to upper part of the water column.

Compatible Tankmates For The Danio

As we said, Danios can be found in most freshwater aquariums. They’re very versatile.

If you’re going to put Danios in a community tank, they will do well with other fast-moving freshwater fish such as Gouramis, Corydoras, Tetras, Platies, and Gouramis. They also go along well with bottom-dwelling fish like loaches.

Their exuberance and curious personality are what make them the perfect dither fish for shy or aggressive species such as Angelfish and Cichlids. But caution should be taken with tank mates that have long-flowing fins as the Danios could attack these. We provide clear and easy guidelines in “Are Danios And Angelfish Compatible Tank Mates?” to help you out.

Even GloFish Danios, which are just glow-in-the-dark Zebra Danios, can go along well with these fish. We have fish compatibility guidelines and Molly-Danio combo tips in “Can Glofish Live With Mollies?”. The important thing for any schooling species is that they are in their complete schools.

White Cloud Mountain Minnow Chinnese Danio
White Cloud Mountain Minnow Chinese Danio

If you’re interested in putting GloFish Danios with other types of GloFish or you just want more information on GloFish Danios, refer to information in “How To Care For Glofish? The Ultimate Guide”.

Danios Sexing And Breeding

It is interesting to note that despite their size, Danios pair for life. And it’s quite easy to spot the male from the female.

Females are more rounded at the belly and more torpedo-shaped. Males, on the other hand, are more elongated and slim with a bit more gold shine on their backs. They mature at about 2 months of age and can spawn at least 100 eggs every 2 weeks, given the right conditions.

Danios are very active to the point that they are labeled invasive. So if you don’t want them breeding, just leave them be. Danios are egg scatterers and tend to eat their eggs as well as other species’.

But if you prefer your Danios multiplying, you must have more room for them in your tank. A group of 6 Zebra Danios in a 20-gallon tank won’t be enough when you add juveniles. Plan ahead and make room before you buy your first tank so you won’t have to waste resources overhauling your setup.

We recommend reading “Will Your Zebra Danios Eat A Guppy’s Fry? ” as we discuss methods that will help you preserve as many babies as you can.

What Makes Your Danios Sick? Danios Diseases

Danios are not prone to disease but they do get sick from time to time.

Danios’ are very sensitive to sudden spikes in temperature and the presence of toxins like nitrites and ammonia. So even if they’re very hardy, it is important to maintain a regular water change and cleaning schedule. Otherwise, the fish will get stressed and succumb to various diseases.

One obvious symptom of any kind of disease is the lack of appetite. If your fish is not eating, something is wrong. At this point, you should look for symptoms such as lethargy, lesions, white or yellow spots, flashing, bloating or swelling, stringy poop, or torn fins.

Purple Passion Danio -Rosy Danio
Purple Passion Danio -Rosy Danio

In some of our articles, we mention that Danios can tolerate up to 82°F (normally 78°F). That high temperature is actually for treating symptoms of parasitic diseases like ich or velvet (gold dust disease). The parasites detach with the heat but are not killed.

Parasitic diseases should be treated with saltwater baths and products like Ich-X. Follow the recommended dosage and use a hospital tank if necessary.

Other diseases that may plague Danios are bacterial infections stemming from wounds or dirty water. Try to look for bullies in the community tank and separate them if necessary. If that’s not the problem, it’s most likely (again) dirty water.

Bacterial infections can be cured with antibiotics in their early stages.

Conclusion

Keeping Danios is simple as long as you put a school of them in a clean, good-sized tank with compatible tank mates, consistent water parameters, and appropriate food. And please, don’t forget your regular water changes.

This pretty simple setup makes them perfect as a beginner fish and a favorite among veteran hobbyists. Yes, even those with years and years of experience still enjoy taking care of Danios. They’re that irresistible!

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