The beautiful and graceful discus is known as the king of aquarium fish for a good reason. That’s why discus fish care is such a hot topic.
Available in a variety of colors, this impressive and rewarding fish can be the centerpiece to any aquarium. However, they do require a good standard of care, and if the basics aren’t correct then this fish will struggle to thrive.
In this quick and easy guide to discus fish care, I am going to cover all the basics around setting up a tank and creating a suitable environment for this species. I will also talk about water quality, feeding, behavior, health, and the basics of breeding.
But don’t worry, once you understand the practical actions you need to take, discus care is not as difficult as many people say, and with some time you can quickly become competent.
Origin: Discus were first discovered in 1840, by Dr. Johann Jacob Heckel. He found them in the freshwater tributaries of the Amazon basin. Because of their beauty, people around the world quickly became enthusiastic about this species.
Reviewed in 2006, there are now three recognize species of discus: S. aequifasciatus, S. discus and S. tarzoo. However, there is some debate about how many distinct species there really are, and in 2011, a molecular study found five distinct groups.
Discus Sizes: Although small at birth, at around 2 inches long, adult discus can easily reach 6 inches. If kept in optimal conditions, discus can grow up to 8 inches.
Because of this large size, and their overall shape and tail dimensions, you will need to provide a large aquarium.
The Basics Of Caring For Discus Fish
Discus are a social species, preferring to live in groups, which offers them interaction and a feeling of safety. So most people own several of these fish, which added to their potential size and need to swim and hide, means that aquarium size is something that needs to be factored in from the start.
Because of their origins, the discus will only thrive in very specific water conditions. If these exact conditions are not achieved, then fish can quickly fall into poor health, or even die. This is why the inexperienced owner needs to ensure that they understand the requirements, and have equipment available from the start to achieve them.
One final point on the basics of discus care is their lifespan. A well looked after adult fish can live for as long as 15 years. Although this is not common, you have to understand that the decision to buy this type of fish can be a long-term commitment.
Discus Tank Size
Discus are better suited for large aquariums. A large discus tank is required for several key reasons:
- Larger volumes of water make it easier to maintain water quality
- Discus are social fish, it’s recommended to keep more than one in the tank
- They can grow to quite a large size, which can be problematic if you have several
- If you intend to breed your discus then you will certainly need a large tank
- These fish like to swim and hide, so you have to provide that environment
So it will depend on the number of fish you are intending to keep, and whether you are intending to breed discus. These are the key considerations before purchasing your aquarium.
As a general guide, you should allow 10 gallons per fish in the tank. In terms of a basic tank size, most people recommend starting as you mean to go on, by buying a large capacity aquarium.
What constitutes a large discus tank is of course is subjective. But breeders recommend a minimum tank size for discus be at least 50 gallons, or 36 inches x 18 inches x 18 inches.
However, if you are only starting with a few fish, then you could choose a smaller tank, and then purchase a bigger one as the fish grows. A smaller tank can also be useful to have if you intend to breed your discus, which I will discuss in detail later.
Getting The Water Right For Discus Fish
When it comes to discus fish care, the absolutely most essential part of ensuring that they are healthy and thrive, is getting the water conditions correct.
These fish are very sensitive to temperature and the type of water they are in. If this is not kept within the correct parameters, and hygiene is not impeccable, it can lead to a variety of illnesses and problems, such as:
- Breathing problems
- Lack of balance
- Fin rot
- Tail rot
- Skin ulcers
- Parasite infections
- Bacterial infections
- Cloudy eye
- Discus plague
Keeping the water clean, at the correct temperature, and within the correct boundaries for acidity and mineral content, will ensure the best chance of thriving. In fact, most diseases and problems with these fish can be treated primarily through increasing the frequency at which water is changed and processed.
As a rule, you should change 25% of the water each week, but more is better if you can handle it, and if it won’t upset the fish.
In terms of the correct temperature for the water you keep in your aquarium, again, discus are incredibly picky about temperature. They are classified as a warm water tropical fish, and should be kept within a tight temperature range between 82°F and 86°F.
The lower temperature is usually adequate, but if the fish has an illness, they tend to get well more quickly at the higher temperature. However, higher temperatures can also trigger breeding behavior.
Discus are very sensitive to pH (acidity) and KH (carbonates), as well as ammonia and nitrate levels. They tend to thrive in softer water.
Specifically, the pH of your aquarium water should be a minimum of 4.0, and a maximum of 7.0, with pH 6.0 being the figure to try and achieve. Just as important is stability. Discus have been known to thrive in levels as high as pH 7.8, but it is the fluctuations that can problems.
Planted aquariums will require CO2 injection to survive. These types of aquarium, which are what you should be trying to achieve as the idea home for your discus, commonly have a lower and more stable pH level.
In terms of nitrate, there should be absolutely none in the tank at all. Discus are extremely susceptible to even the smallest amount of nitrate, which is why it should be carefully monitored for.
Sometimes confused with nitrate, nitrates should be kept as close to 0 as possible, with any reading above 20 ppm being dangerous.
Ammonia levels should also be kept close to zero. Breathing and color will be affected if ammonia levels rise above even a few parts per million. You should do an immediate 75% water change should ammonia be detected in the tank.
So as you can see, it’s the precise water conditions required that make discus care more difficult to care for than a lot of aquarium fish. They’re not an easy pet to look after, because of the specific conditions that they thrive in.
Understanding what is required, and investing in the equipment to maintain the exact environment required, are key to developing your knowledge and skills as an owner of healthy discus.
Creating A Great Habitat For Your Discus
The natural habitat of the discus is the Amazon basin, with driftwood and wide variety of plant species.
It is possible to keep these fish in a completely bare tank, but from both your point of view and theirs, this is not ideal.
A shallow layer of clean aquarium gravel, around 2” deep, creates a good base. On top of that, you can position long stem plants and lower foreground plants. These will create an environment that look good, and through which the fish can swim, and hide.
It’s recommended to add in driftwood. This is a safe and attractive decoration that will be aesthetically pleasing, and also offer a practical place to swim and hide for your fish. It also releases tannins that help reduce stress within discus.
Once you’ve created your environment, as well as regular water changes, you should also keep the plants healthy. You will have to research which plants fit with the conditions in the aquarium. This can be problematic however, and I will talk about it further when I discuss lighting requirements.
Discus can create quite a lot of debris within the tank. Their sensitivity can lead to health problems if this debris builds up, especially if it sinks to the bottom of the tank and builds up in the gravel.
Daily cleaning using a small fish net is therefore essential. You should remove any food that has not been consumed, as well as any other solids floating on the surface, or within the tank. This will help to keep the environment you created clean, and make it easier to maintain the exact conditions the discus fish requires to live healthily.
Lighting In A Discus Tank
Discus fish come from a naturally shaded environment, being the Amazon River and its tributaries, which are primarily covered by tropical rainforest. On top of this, the water of the Amazon is generally dark in nature. It is rich in organic chemicals, and especially tannins, which keep the water dark and lower in pH.
It should be immediately obvious that discus fish are naturally used to low levels of light, and are more at home, importantly they will feel safe, in lower levels of light.
In fact, bright aquarium lighting can stress discus out and cause emotional problems.
It’s best to stick to natural lighting if possible. You should also position your tank away from direct sunlight. A quiet and shaded corner of a room will be perfectly adequate. You could lower the light levels by placing dark panels on the sides and back of the tank, and across the top, to minimize light intruding into the water.
Aquarium lights are usually talked about within the terms of watts per gallon. Although this isn’t universal, and can be confusing, it does adequately explain the type of light this fish require. Around 1.5 watts per gallon of light is perfectly adequate.
This low light level does create a slight problem when it comes to providing plants in the aquarium for your fish to swim around and hide in. Most aquarium plants cannot cope with the low light levels that discus fish enjoy. If you are faced with this problem, I highly recommend you provide decorations such as driftwood or tunnels to help your discus feel more comfortable.
Acclimating Discus Fish To A New Tank
Before you put your fish into the aquarium environment you have created, it’s vital that it’s chemically tested to make sure that it falls within the parameters I have already discussed, namely:
- Water temperature between 82°F and 86°F
- Water pH level as close to pH 6.0 as possible
- Zero ammonia
- Zero nitrates
If you have a quarantine tank, one thing I recommend is add de-worming medication to the water before introducing them to the tank itself. Although this could stress the fish out, keeping them in a different tank with this medication for a short period, will remove the risk of worms within the aquarium.
The next step of acclimation is to get them used to the water that is in the tank itself.
Within the container they are being held in, you should drain away as much water as possible. Then set up a siphon tube with tap going from the tank to the container. Create a water flow that allows a slow rate of water introduction, a few drips per second at most.
Allow this to happen for around 30 minutes, until the bucket is nearly full. Watch the fish carefully all the way through this process.
If they seem settled, use a soft mesh net to collect the fish and transfer them, one at a time, into the main tank. Monitor the mood and progress of each fish carefully for a few minutes before repeating the process.
Once the fish have been transferred, you can siphon the water from the bucket back into the tank. You should then carefully check for all the parameters I have discussed around the chemical composition of the water and temperature. If it’s not as required, you may have to perform an immediate partial water change to correct it.
Discus Diet & Feeding
Feeding is the other key area in which you can directly intervene in keeping your discus fish healthy.
What’s vital is to give variety that balances all the nutritional needs your fish will require. This can be a mix of individual things, and food mixes that you can buy. Specifically, frozen food mixes specifically designed for discus fish.
Discus are basically carnivorous in nature, which is why a meat diet should be tailored for this part of their nature.
Generally, giving your fish a good blend of the following will be ideal:
- Live or frozen bloodworms
- Glass worms
- Beef heart
- High-quality Discus pellets
- Vitamin-rich flakes
- Crude Protein min 50% Crude Fat min 6% Crude Fiber max 3% Moisture max...
Sprinkling vitamin-rich flakes on the surface of the water can really help to keep the fish healthy. However you do need to understand how the discus fish prefers to feed.
This type of fish prefers to be fed in the middle of its tank. They also don’t tend to pay as much attention to food that floats on the water surface, or near the side of the tank. So bear this in mind when feeding your discus.
One solution is to have a feeder cone in the tank that can contain blood worms beef heart. This gets rid of the problem of the fish missing the food.
Although discus can actually go a couple of weeks without feeding, it’s ideal to feed them several times a day, with three times a day being a good number. This doesn’t mean feeding them loads of food each time. Give them just enough to consume in a couple of minutes of feeding.
Almost as important as what you feed your fish, is cleaning up after they eat. Uneaten food, especially fresh food, and flakes left on the surface, should be removed from the tank immediately after they have stopped feeding and moved away.
Beef heart especially can be problematic. It carries the potential for bacteria and parasites to grow if it is left in the tank. If beef heart is left in the tank for too long, then you dramatically raise the possibility of the tank becoming polluted.
A top tip is to turn off the water filters when you feed the fish. This will stop food being drawn to the filters, and being kept in the tank where it cannot be easily fished out. Feed the fish small amounts, observe where it is falling, and then make sure you take it straight out so that there is no contamination problem.
The discus is a social fish, and thrives best in small communities. They prefer to stay in groups, and within the tank will tend to swim around with others.
This mimics the behavior that they use for social interaction, breeding and protection when feeding in freshwater rivers.
The time when they are not social is, as in common with many species, when it comes to mating. Adults looking for breeding partners can become incredibly aggressive, some people describe it as ferocious, with other fish. Male discus can bully other males to drive them away, which can create conflict within the small environment of the tank.
If you are not intending to breed your fish, then this is not a problem. Although you will occasionally get this aggressive behavior, it is only when the temperature of the water is raised, mimicking the warmer temperatures of the breeding season, that starts to provoke this action.
Discus Tank Mates
As you probably now realize, the best tank mates for discus fish are other discus. A small group will be perfectly happy in each other’s company.
But if you have a large tank, or you would only like handful of discus, then you may have to consider adding other fish for variety and interaction.
Only a few fish can create boredom. This can lead to isolation problems such as disorientation. This can be rectified with fish from other species, it’s not just about having only discus in the tank.
Some compatible companion species include:
- Cardinal Tetras
- Corydoras Catfish
- Angel Fish
Obviously if you intend to populate your tank with any of these additional species, you will have to do some research into the precise conditions in which you can create a harmony within the tank. You will need to know how these species interact with each other, and other species before introducing them.
Breeding Discus Fish
The breeding of discus fish is a large topic in itself, and if you are considering this is a goal, then you will need to do a lot of research to successfully achieve it.
The problem is that they only breed under very specific circumstances, which are difficult to achieve within a aquarium environment. In fact, until recently, very few had been successfully born and bred in captivity.
However, that has changed as more knowledge has been gained around what helps these fish to successfully mate. Now, a dedicated hobbyist can successfully breed their discus by following a few simple steps.
But you should be aware that it can take a long time to achieve. It can take months, even a year, for this journey to complete.
The first consideration is that a couple will not spawn if the environment is too shallow. So if you are keeping your fish in an aquarium that is not at least 15 inches deep, then you will struggle to initiate successful breeding.
As well as being 15 inches deep as a minimum, the tank should not be huge, as the breeding pair should be kept in close proximity. Some people suggest a 15 inch cube tank. However, this is sometimes deemed less humane, and a more spacious size recommended.
To initiate breeding, the summer Amazon temperature and water must be achieved. This means creating an environment the mimics that.
The temperature should be kept at or above 86°F to encourage the discus into initiating mating behavior
In addition, humidity and water changes happen in the summer Amazon rain storm months. Mud and other substrate collect during these months, darkening the water and changing its composition.
To mimic these changes for your fish, the water should be kept as soft as possible, around 1-4 dH. This creates a problem in that soft water is less stable, which means daily checking of the water to ensure that the parameters are maintained.
Nitrates have to be continuously eliminated, which means more frequent water changes, including a complete change every week. These water changes are vital, as they also help to signify breeding to the fish.
In terms of food, high protein ones are best. Balance the diet, but keep it heavily proteins focused. Most professional discus breeders use beef heart primarily, topped up with blood worms. Keep vitamins in the diet, nutrient-rich shredded matter, such as spinach, can be added to the water as well.
When the fish lay eggs, they need to be positioned so that they can be seen. An upturned pot made of clay, is ideal for this. You can buy professional quality plastic cones, but these are obviously more money, although they have improved proven results.
Spawning & Raising Young Discus
If your fish spawn then eggs will be laid approximately weekly, for up to 15 weeks in total. This cycle occurs twice a year in most cases. You can achieve this through creating the situation I have just discussed in terms of environment balance.
Discus mate for life, so a breeding pair can be rewarding and profitable for years to come, if you can get them to mate initially, and then keep creating those conditions again.
Once the eggs have been laid on the surface of the pot you have provided, they will sit there as opaque spheres in their thousands. The fish will fan these eggs to aerate them periodically. Don’t worry if you see your fish eating eggs, they do this to dispose of dead eggs that could rot and spread disease.
After laying, the eggs will hatch within about 48 hours. Within a couple of days after hatching the baby discus should be swimming freely. They will then grow quite rapidly.
Known as Fry, they can stay close to their parents for quite a long period of time in the wild. However, young discus can be quite aggressive towards their parents, and in captivity most are removed after a couple of weeks. At this stage, the young within the aquarium will be fed using the normal food balance.
Discus Fish Care: Summary
Although discus can be challenging to look after correctly, if you understand the environment they need, and invest time, effort and money in achieving it, then it is perfectly possible to own and breed discus.
Although this guide may sound quite involved, discus care basics are quite straightforward once you master them:
- Keep the tank in a quiet place, away from sunlight and in darker conditions
- Isolate new fish, and introduce them into the water, and then into the tank gradually
- Keep the water temperature managed between 82°F and 86°F
- Create an environment that contains plants so that your fish can hide and don’t feel stressed
- Have several fish in the tank to create natural group conditions
- Get the right food balance
- Maintain cleanliness in the tank using filters and regular cleaning of matter
- Keep pH level stable
- Monitor ammonia and nitrate levels, and replace water where necessary
- Completely change tank water weekly if possible, but at least 25% as a minimum
Last update on 2018-10-18 at 13:55 / Affiliate links / Images from Amazon Product Advertising API