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. Unfortunately, not everyone is able to keep up with these strict rules. Many people use simpler methods. We have many years of experience keeping discus, both at home and in the fish store, as well as helping customers to be successful with their pets. This care guide is based on our experience and provides useful tips and practical advice for anyone starting a discus tank.

What is the ideal temperature for Discus Fish?

To keep happy discus, raise the water temperature. We recommend that water temperatures be raised from 85 to 86F. Because discus farms keep their waters at these temperatures and it causes discomfort when we attempt to force them down to cool down. The heat keeps your discus active. Their metabolisms work well and their growth rate is faster. 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.

Water hardness and pH are also important environmental factors to be aware of. The recommended pH can be controversial since many people place great emphasis on this factor. We have found that both wild-caught discus and captive-bred discus perform well at pH levels between 6.8 to 7.6. The same holds true for water hardness. Discus can be fine with water that is soft to moderately hard. We haven’t kept German-bred discus yet, but they’re known for tolerating higher pH and harder water. If you’re focused on breeding and raising discus fry, you need much lower pH and water hardness, but if you’re simply keeping them for enjoyment, these two water parameters aren’t as important.

Although aquarium plants and tank mates are possible for discus aquariums, they must be capable of handling the required hot water temperatures.

What size tank do you need for discus?

Bigger is always better, so we personally recommend a 75-gallon aquarium or larger. A 55-gallon tank is possible, but you will need to water change a lot. Keep in mind that these fish can get very large, often 5 to 7 inch diameter, if you’re doing it right. Heating up the tank can increase their metabolism, which means that you need to feed them more. People recommend frequent water changes.

Many customers ask us, “Can I keep one discus?” Technically, the answer is yes. For example, although dogs are technically considered pack animals, many people only have one dog and keep them at home. It isn’t ideal but it is possible. Discus is the same.

However, they are schooling fish by nature and are much happier when surrounded by a large group of their own kind. Plus, as a type of cichlid, they may start to bully each other if you don’t a decent-sized group. For your 75-gallon tank, purchase 10 to 12 juveniles simultaneously to reduce aggression. (You want them to be approximately the same size so that no one gets outcompeted for food.) You’ll be able identify the males who are rowdy and can rehome them to the fish shop as they grow in size. Eventually, you should end up with a nice, relatively peaceful group of six adult discus with mostly females and maybe a couple of 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 fern, bacopa and sword plants. Because the water temperature rises, it decreases oxygen levels. In the summer when the weather gets hotter than normal, an air stone can help decrease the risk of having low oxygen levels.

Create a bigger school of juvenile discus first, and then eliminate the most aggressive members over time.

Does Discus Really Require Daily Water Changes?

It depends. Keep in mind that water changes are intended to eliminate any waste buildup. Water changes are different for each aquarium. There are many factors to consider, including how big your aquarium is and how many fish you keep. As a rule of thumb, we recommend that the nitrate concentration in your tank be below 40ppm for those with planted tanks and below 20ppm for those without.

To figure out how often you need to do water changes on your aquarium, get an aquarium water test kit and download our free infographic that guides you step-by-step through the process.

What Fish Can Be Kept With Discus?

Tank mates must meet two criteria: they should be able to live in high temperatures and they cannot outcompete the discus for food. Discus are slow feeders. If they are placed with large schools of tetras or barbs, the discus will be less likely to survive. They can also be too fast for other hot water fish such as clown loaches and German blue rams.

Consider starting with a discus-only tank, where they will be the main fish. Once they start eating well you might add Sterbai cory catfish or cardinal tetras to your tank. Be careful not to have too many tank buddies, as discus can lose 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?

Many people give discus mouths foods that are too large. Therefore, if you see them eating the food, spitting it out, and then mouthing it again, you may have a problem with the size of the food.

Frozen bloodworms look great as they are small and easy to slurp up. But discus can easily become dependent on them. It is important to provide them with a variety of small foods that will give them all the nutrition they need. Hikari Vibra Bites is a great option. Others include live or frozen brine shrimp, blackworms or microworms, as well as freeze-dried or live blackworms.

Why is 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. To minimize bullying, make sure you buy a group of them.

It’s much simpler to keep discus fun than taking care of breeding and raising discus fry.

How can you keep Discus fish happy?

The main takeaway from this care guide is to

reduce stress

. Make sure to heat the water, keep it stable and clean, and make sure they are properly fed. Do not allow children to touch the glass and limit traffic around the tank. Their aquarium should not be placed next to any flashing lights or loud noises. Anything you can do for these shy creatures will make them feel more secure and help to improve their quality of life.

Don’t forget about your stress levels! A lot of novice discus owners are too worried about inflicting damage to their discus. They spend far too much time worrying instead of relaxing and enjoying their incredible beauty. You can have a discus tank that is enjoyable and profitable for many years with these guidelines.

Want to read more blog posts like this? Subscribe to our e-newsletter to stay up to date on our latest articles, videos, events, and more.