Care Guide for Discus Fish – The King of the Aquarium
Discus fish are one of the most beautiful freshwater fish in the hobby, known for their spectacular colors and large, circular shape. Discus fish are notoriously difficult to maintain. Many forums recommend strict water changes, such as 100% every day, which is something many Internet forums encourage. In reality, only a small percentage of people are able to follow those rules, and the rest of the world uses more low maintenance methods. We’ve spent many years keeping discus personally at home, caring for them in our fish store, and helping customers be successful with them. This care guide, based on our experiences, offers useful tips and practical advice to beginners who are starting their first discus aquarium.
What is the Ideal Temperature to Fish Discus?
It is easy to keep discus happy by raising the water temperature. We recommend that the water temperature be between 85 and 86 degrees F. This is because discus farms that we source them from keep their water at these temperatures. If we force them to cool off, it can cause discomfort. Your discus will be more active if the heat is high. They’ll grow faster and show better colors if their metabolism is humming along. So if you want to successfully care for discus, be willing to make this necessary change, which may differ from your normal fish keeping habits.
You should also consider pH and water hardness. It is not easy to determine the pH level that should be used, as many people put a lot of emphasis on it. Our experience shows that both wild-caught and captive bred discus thrive when pH levels range between 6.8 and 7.6. The same thing applies with water hardness; discus are usually fine with soft to medium hardness. While we haven’t had the pleasure of keeping German-bred discus yet to this day, it is known that they can tolerate higher pH and more hard water. You need a lower pH and a higher water hardness if you are concentrating on raising discus fry. If you keep them for enjoyment, however, these parameters won’t be as important.
It is possible to have aquarium plants or tank mates in discus tanks. However, they must be able and able to withstand the hot water temperature.
What Size Tank Do You Need for Discus?
A larger aquarium is always better. We recommend a 75-gallon or larger tank. A 55-gallon tank is possible, but you will need to water change a lot. Remember that these fish get big, usually 5 to 7 inches in diameter if you’re doing things right. You can also increase their metabolism by heating the tank. This means they will eat more and produce more waste. (That’s why people recommend doing all those frequent water changes.)
Many customers ask us, “Can I keep one discus?” Technically, the answer is yes. For example, dogs are technically pack animals, yet many people keep just one and then leave them home all day by themselves. It’s not ideal, but it’s doable. The same thing applies with discus.
They are nature-selecting school fish and will be happier if they have a larger group. As a type, cichlids can bully each other, so make sure you have enough. You can reduce this aggression by purchasing 10-12 juveniles for your 75 gallon tank. You want them all to be roughly the same size so they can all compete for food. As they get bigger, you’ll be able to identify the rowdy males and rehome them back to the fish store. You will eventually have a peaceful group of six adult discus, mostly females, with maybe one or two males.
For tank setup, they can be placed in a plant tank. But make sure that you find plants that can withstand high temperatures like anubias. Java ferns, sword plants and microswords are all good options. Air stones are also recommended as the higher water temperatures can reduce the oxygen level. An air stone can be used to reduce the chance of low oxygen levels in summer, when temperatures are higher than usual.
Start with a larger juvenile discus school and then gradually remove the more aggressive ones.
Does Discus really need daily water changes?
It depends. It all depends. Every aquarium is different so the frequency and amount of water changes will vary. Several considerations include how large your tank is, how many fish you have, how much you feed them, and how much biological filtration (e.g., beneficial bacteria and live plants) you have. We recommend that you keep the nitrate levels below 40 ppm for plants tanks and below 20 ppm if you have non-planted tanks.
Get an aquarium water test kit to determine how often water changes are needed for your aquarium. You can also download our free infographic which guides you through the process step-by-step.
What fish can be kept with Discus?
Tank mates should meet two requirements: they must be able to survive in high temperatures, and they must not outcompete the discus when it comes to food. Discus are slow feeders so they will lose their race if they are paired with fast, bullet-shaped fish like barbs or huge schools of Tetras. Even hot water fish such a clown loaches, German blu rams and angelfish can be too fast to them.
Consider starting with a discus-only tank, where they will be the main fish. Once you get them eating well, consider gradually adding cardinal tetras, Sterbai cory catfish, or maybe a bristlenose pleco. You should limit the number of tank mates or the discus might lose its nutrition.
Cardinal tetras are a popular tank mate for discus tanks, but don’t get so many that they outcompete the discus for food.
What is the best food for discus fish?
Most people feed them foods that are way too big, not realizing that discus mouths are quite small. You may suspect that they are eating too much food.
Frozen bloodworms are great because their skinny shape is perfect for slurping up, but discus can get addicted to them quite easily. Make sure to feed them a wide variety of small foods to cover all the nutrients they need. We’ve had good luck with prepared foods like Hikari Vibra Bites, Sera Discus Granules, Tetra Discus Granules, and Hikari Discus Bio-Gold. You can also try frozen brine shrimps, freeze-dried blackworms and microworms.
Why Are Discus Fish so Expensive?
This was something we mentioned previously. Tank conditions are essential for raising fry and breeding them. It’s very time- and labor-intensive work, especially since discus take longer to reach full adult size compared to other cheaper fish like guppies. You can buy discus from local breeders, fish stores, or even online, but if you’ve never kept discus before, our best advice is to stay away from the price extremes. Don’t purchase the cheapest discus that might have quality issues or the $300 adults that could die due to your lack of experience. Just remember to purchase a group of them that are all the same size to minimize bullying.
Keeping discus for fun is much easier than the high-maintenance care required for breeding and raising discus fry.
How can you keep Discus fish happy?
This care guide’s main message is to
reduce stress
. Make sure to heat the water, keep it stable and clean, and make sure they are properly fed. Limit the number of people near the tank and don’t let children tap on it. Also, don’t put their aquarium right next to the TV with lots of loud noises and flashing lights. Anything you can do to help these shy creatures feel safe will go a long way in enhancing their health and quality of life.
Last but not least, reduce your stress. Many discus beginners spend too much time worrying about whether they will accidentally damage their discus. Instead of enjoying their magnificent beauty and relaxing, many people don’t realize how important it is to reduce their stress. You can have a discus tank that is enjoyable and profitable for many years with these guidelines.
More blog posts similar to this one? Subscribe to our e-newsletter to stay up to date on our latest articles, videos, events, and more.