Everything About Discus Fish Tank: Size, Watering, Tank mate And More

While they can be difficult to raise successfully for inexperienced aquarium hobbyists, discus fish are among the most popular species in the aquarium hobby industry. One of the reasons why these fish can be difficult to raise successfully is their sensitivity to inconsistent water parameters.

These fish are native to the Amazon River basin, where water temperatures rarely fluctuate more than half a degree at some time throughout the year. As a result, constant temperature in the domestic aquarium is necessary for these fish to thrive. In addition to maintaining stable water temperature, discus fish also have certain preferences for tank size and water chemistry, as well as the decoration of the tank and tank mates.

Preferred Tank Size For Discus Fish

Because discus fish reach an average size between 20 and 25 centimeters, they require a large tank, preferably tall. For a single fish, a minimum tank capacity of 50 gallons is recommended. However, discus fish are school fish, so it is better to keep no less than three at a time.

To determine what tank size is needed, start with a 50-gallon base and add an additional 10 gallons for each additional discus fish. Like all fish, discus fish need adequate space to swim and grow. If the tank is too small or full, it is likely that discus fish will get stressed and end up getting sick.

Potential tankmates should also be considered when determining the appropriate size for a disk tank. While an 80-gallon tank may be suitable for four discus fish, adding tank mates such as tetras may require a change to a larger tank.

The general rule to follow for the community fish is to allow one gallon of tank capacity per inch of fish. A 100-gallon tank that houses four discus fish (50 gallons for the first discus and 3 x 10 gallons for the additional ones) could safely hold 20 inches of additional stock.

Top Suggestion: When performing these calculations, use the adult fish size instead of its size when purchased to avoid overcrowding in the future.

Water Chemistry For Discus Fish

Discus fish are notoriously sensitive to changes in water chemistry, which is one of the qualities that makes them somewhat difficult to maintain in the domestic aquarium.

The Amazon River, the native environment of discus fish, receives an almost constant flow of freshwater due to the amount of rainfall the Amazon region receives each year. As such, discus fish require extremely high water quality, which can only be achieved through frequent water changes and adequate filtration.

In addition to receiving a constant influx of freshwater, the Amazon River tends to remain fairly stable temperature around 80 ° Fahrenheit. In the domestic aquarium, it has been discovered that discus fish are better equipped to withstand diseases at higher water temperatures between 80 ° and 86 ° Fahrenheit.

However, such high temperatures can lead to increased algae growth, so many aquarists recommend a tank temperature of around 82 ° Fahrenheit. Oxygenation is another concern at higher water temperatures. Growing live plants in a disk tank can help counteract the lower oxygen capacity of warm water.

The Amazon River generally maintains a pH between 4.0 and 7.0, although most discus fish prefer acidic water with a pH in the range of 6.0 to 6.5. The PH can be controlled by the addition of commercial compounds in unplanted tanks, but, in planted tanks, these methods can lead to overgrowth of algae.

Adding sodium bicarbonate (NaHCO3) to the water tank to increase KH or alkalinity, and injecting carbon dioxide (CO2) to buffer it is a more traditional method.

In addition to these methods, there are several ways to naturally increase or buffer the pH in a discus fish tank. Insert peat into the filter pad or add black water extract are two simple and natural ways to alter the chemistry of water in a disk tank to more accurately mimic the conditions in the Amazon River.

The final component of water chemistry that should be considered when maintaining a disk tank is water hardness. Water hardness is usually measured in terms of general hardness (GH) or carbonate hardness (KH), also known as alkalinity.

The water in the Amazon River is relatively low in mineral content, which makes it quite “soft.” Therefore, the recommended water hardness for disc tanks is between 0 ° and 8 ° DH, although some species can tolerate a hardness of up to 12 °.

Filtration, Heating, And Lighting Of The Tank

In their native habitat in the Amazon River basin, discus fish are used to heat slow-moving water and low light. In order for discus fish to thrive in captivity, these conditions must be reproduced as closely as possible.

To achieve adequate filtration without creating too strong a current, some fish breeders use multiple filters. A power filter is recommended for large tanks to provide adequate aeration and to facilitate both mechanical and chemical filtration.

Sponge filters are excellent supplementary filters for discus fish tanks because they provide biological filtration and also help control the accumulation of solid wastes and wastes. When selecting a filter for a discus fish tank, consider the tank size and select a filter that has a low flow output setting.

There are several types of aquarium heaters on the market, but, among these types, two are most frequently recommended for discus tanks.

A submersible aquarium heater is one that can be completed submerged in the tank. This type of heater should be placed horizontally along the rear wall of the tank near the bottom. This position will allow for more uniform heat distribution.

Hanging aquarium heaters are those that can be inserted vertically into the aquarium and suspended by using suction cups or a plastic or metal hanging device. These heaters are somewhat less efficient than submersible heaters because the heat distribution is concentrated around the area of ​​the tank where the heater is hung.

Because aquarium heaters come in a variety of sizes, it is imperative to select the size that best suits the tank capacity. For particularly large tanks, it may be convenient to implement two aquarium heaters smaller than one large. This will not only ensure uniform heat distribution but also, if one of the heaters fails, the resulting drop in tank temperature will be less sudden.

When exploring the selection of aquarium heaters, look for a model that includes an external control option. This option allows the fan to monitor the device to make sure it works correctly.

Using a thermometer inside the tank is another simple way to monitor the temperature of the tank, as well as the function of the tank heaters.

The water in the Amazon River contains tannins, a substance that reduces sunlight and makes the water look cloudy. To mimic this condition in a domestic discus fish tank, it is necessary to provide dim lighting.

There are a variety of options when it comes to aquarium lighting, but not all types are recommended for disc tanks. Fluorescent lighting is the cheapest option and uses the least amount of energy.

The most common way to use this type of lighting is through an aquarium bell. Compact fluorescent lighting is more powerful than normal fluorescent lighting, although the bulbs are usually smaller.

The T-5 high-output fluorescent lights are very compact and powerful, but they emit an intense light that is not recommended for disc fish tanks.

Metal halide lights are recommended for large or deep aquariums such as disc tanks, but they can be quite expensive and should be used with caution because they have high heat production. When using metal halide lights, it is advisable to configure auxiliary fans to prevent the lights from heating the tank.

Light Emitting Diode (LED) lights are becoming increasingly popular because they provide the same power as metal halide lights without dangerous heat. Regardless of the type of bulb, the lighting in a disc tank should be full-spectrum to improve the appearance of the disco fish and to improve the growth of living plants.

Leave the aquarium lighting on for 10 to 12 hours per day in a disc tank and always turn it off at night. If the lighting is too bright, the disc may hide and not come out until the light goes out or the intensity is reduced.

Plant And Aquarium Decoration

Discus fish are a peaceful but often shy species, so they prefer a tank that offers a variety of hiding places.

In their natural habitat, these fish can hide among aquatic plants and the roots of submerged trees, using their natural coloration as a means of camouflage. The incorporation of live aquarium plants in your home’s tank is an excellent way to improve your aesthetic appeal while providing a more natural environment for your fish.

Live plants also help to oxygenate the water in the tank, control the growth of algae and can harbor colonies of beneficial bacteria essential for proper maintenance of the nitrogen cycle.

However, keeping discus fish in a planted tank is somewhat more difficult than keeping a planted tank with other fish species.

Live aquarium plants require nutrients and a supply of carbon dioxide (CO) ready to thrive. In a normal fish tank, plants obtain nutrients from unconsumed foods and organic wastes that accumulate at the bottom of the fish tank.

However, since discus fish are so sensitive to poor water chemistry, it is necessary to make frequent water changes and vacuum the gravel to keep the water quality high. Performing these tasks can not only become a nuisance in a heavily planted tank but can also reduce the number of nutrients available to living plants

In addition to the problems associated with frequent water changes, the water temperature preferred by discus fish is somewhat higher than that in which living plants can thrive.

To keep the plants alive in a discus fish tank, the hobbyist must select varieties that are tolerant of warmer water temperatures.

Some plants that are recommended for discus tanks include those that are native to the Amazon region, such as the Echinodorus family, which includes Amazon swords. Anubias, although native to Africa, are abundant plants that tolerate low light and blend well with swords.

The Java fern, in addition to plants belonging to the Micranthemum and Hydrocotyle families, also works well in a discus fish tank. North American species such as Amoracia aquatica, Bacopa caroliniana, and Samolus parviflorus are adapted to colder waters and should not be kept in a discus tank.

Because discus fish are so large, large rocks and pieces of decorative floating wood are generally not recommended for discus fish tanks. These decorations can end up being obstacles to the discus fish instead of useful hiding places and can also put the disco fish at risk of being injured.

Ideal decorations for a discus fish tank include broadleaf plants, small rocks, and floating plants.

Driftwood can be used in a disc tank if it is placed horizontally along the bottom of the tank instead of standing where the disc fish can bump into it.

Although hiding places are essential for the well-being of discus fish, it is also necessary to provide plenty of open space for swimming.

When decorating a discus fish tank, it is advisable to concentrate the taller plants near the back of the tank, placing the shorter plants in layers towards the front. This arrangement will allow disco fish to hide in the tall plants at the back of the tank when they choose it, leaving most of the space near the front of the tank open for swimming.

Place any tall or vertical tank decoration in the corners or lean them against tank walls so they do not become obstacles that discus fish can run into.

Recommended Tank Mates

Because discus fish have such specific requirements for water quality, it is advisable to design your tank according to the needs of your discus fish. Once you have satisfied the needs of your discus fish, you can start thinking about adding another fish that can fit the parameters of the existing tank; Don’t try to add discus fish to an already established community tank because the water quality may not be high enough to keep your fish disc healthy.

Keep in mind that discus fish are school fish and should be kept with others of their own species, in addition to any other tank mates they want to keep.

If you ask around, many hobbyists will tell you that Discus Fish should stay alone. THAT IS TO SAY, they shouldn’t have tank mates since they don’t compete well with the most aggressive eaters that will get to the food before the discus fish even know it’s in the tank. However, you can still achieve some tank mates with careful planning.

When selecting aquarium mates for your discus fish, it would do well to remember that the discus fish is peaceful and not aggressive. This being the case, it is advisable to pair the discus fish with other fish in the community, particularly the schooling varieties.

Discus fish may be tentative in the domestic aquarium, but if they see other schooling fish out in the open, they may feel more comfortable and are less likely to hide among the plants in their tank.

Many hobbyists have succeeded in keeping their discus fish with some of the smallest species of gourami, such as pearl gouramis, but the blue and gold gouramis are too large and too aggressive to keep with the discus fish.

Some of the best tank mates for discus fish are the characins. Characin is a family of tropical freshwater fish that includes tetras. Because many of the species that belong to this family are also native to the Amazonian regions of Central and South America, they are a good option for a discus fish tank. In addition, tetras are generally small and peaceful fish that are not likely to intimidate discus fish. Popular tetra species that can be kept with discus fish include neon tetras, bright light tetras, bleeding heart tetras, and rummy nose tetras.

In addition to tetras, a variety of bottom feeders can be safely kept in a tank with discus fish. These work well because they will pick up the food that the discus fish miss.

Corydoras catfish, or cories, is still relatively small and is an excellent community fish. Also a variety of schooling fish, the cories will make your discus fish more comfortable while helping to control the accumulation of debris at the bottom of your discus fish tank.

Other bottom feeders should also be considered, such as small Plecostomus, Siamese algae eaters, Loaches and Ottocinclus.

If you keep Ottocinclus or Plecostomus, be sure to provide many algae wafers or spirulina discs to prevent these fish from being tempted to feed on the mucus layer that naturally grows on the skin of your discus fish.

How To Introduce Discus Fish To The Tanck

There are several key components to introduce discus fish into the tank. As is true in regards to all aquarium fish, it is not wise to simply throw a fish into the tank immediately after bringing it home from the pet store.

The temperature of the water in the stock tank from which the discus fish comes may differ from the temperature in the home tank: the rapid change in temperature of the discus fish could cause stress or, in extreme cases, death.

In addition to differences in water temperature, the pH level can also be uneven between the two tanks.

  • Float the bag containing your fish in the new tank for at least half an hour or until the temperature in the bag matches the temperature in the tank
  • Add a small amount of water from the tank to the bag in order to adjust the pH
  • Place the discus fish in the bag and release it in the new tank
  • Look at the fish for signs of stress or difficulty acclimatizing

When adding the first fish to a discus fish tank, the above procedure will be sufficient, but a different procedure is necessary when introducing additional fish into an already established tank.

Even if they appear to be healthy, discus fish from the pet store can carry the disease. To avoid infecting the entire tank with the addition of a sick fish, it is advisable to quarantine new fish for at least weeks.

Set up a quarantine tank that is at least 20 gallons in size and adjust the water chemistry and tank parameters to match as much as possible with the main tank.

Float the bag containing the new discus fish in the quarantine tank following the procedure mentioned above.

During the weeks when the new discus fish is in the quarantine tank, look for signs of illness. If the fish begins to show symptoms, try to identify the disease and start a treatment regimen.  Do not plan to move the fish to the main tank until it has fully recovered.

While the fish is in the quarantine tank, perform routine maintenance tasks such as water changes and water tests to keep the water quality in the quarantine tank high. If, after two weeks, the fish shows no signs of disease, it can be safely moved to the main tank.

To avoid contamination, do not share any equipment including netS, filters, hoses, and buckets between the main tank and the quarantine tank.

Moving Discus Fish To The Tank

Like all aquarium fish, discus fish are living creatures that must be handled with care. If proper care is not taken when moving the discus fish, the fish could be injured or experience undue stress that can lead to illness or death.

To avoid these consequences, discus fish must move slowly and also be given time to adapt to their new environment before being released into the tank.

How To Transfer Discus Fish Using A Mesh Net:

  • Select a net that is large enough to comfortably cradle the fish, when the net has been removed
    from the tank, the captured fish should be able to lie on the bottom of the net. The fish should not lean against the solid frame of the net or stand out from the net itself.
  • Insert the net into the tank and gently pull the fish into the net. If the fish is difficult to catch, try to corner it against the glass or in a corner to prevent it from escaping around the net.
  • Hold the bag or container in which the fish is transferred over the main tank to minimize the amount of time the fish spends out of the water. remove it from the tank
  • Gently turn the net over the transfer vessel and, by hand, release the fish into the water

In the event that it is necessary to relocate a complete discus fish tank, there are some preparations that must be made.

Before moving, be sure to identify the new location of the tank so that it can be configured immediately upon arrival. When it is time to move, transport as much original aquarium water as possible from the aquarium in large plastic buckets.

Use one of the buckets to transport the aquarium gravel, keeping it moist so that the beneficial bacteria that live in the gravel do not die.

By transferring the bacteria from the original discus fish tank to the new tank, the nitrogen cycle can be significantly accelerated and the discus fish will have less waiting time before returning home.

Tips For Moving A Discus Fish Tank

  • Avoid feeding the discus fish for 24 to 48 hours before moving to ensure that the water in the moving containers is kept as clean as possible.
  • Place the discus fish in large buckets or bags filled with water from the original tank, keeping each container limited to one fish. When using buckets, fill the container only 2/3 with water to leave enough room for air
  • Cover the mouth of the buckets with an airtight lid or a plastic trash bag
  • Empty as much water as possible main tank in large plastic buckets and transport them to the new tank location
  • Transport the tank substrate in a large plastic bucket filled with water from the original tank; do not allow the substrate to dry out
  • Install the disc tank in its new location and install all the equipment
  • Pour the aquarium substrate and the original tank water into the new tank
  • Fill the tank to its capacity, add tank decorations and condition the water with your preferred dechlorination solution. Carbon filtration is a way that can greatly reduce chlorine and harmful chemicals (or substances) from tap water. An additional note is that the Python-type refill pipe can be connected directly to your carbon filter and can be used at temperatures acceptable to discus fish. The good thing about tap water filters is that they are relatively cheap and also eliminate harmful impurities from water, including disinfectants such as chlorine. Make sure you have selected one that has been rated for warmer water.
  • Perform a water test to verify the chemistry of the water in the tank; if it is close enough to the usual level in the original tank, it may be safe to introduce the discus fish.
  • Bag the fish individually, adding a small amount of water from the new tank, and float the bags in the new tank for at least half time.
  • Net the fish carefully and release them in the main tank.

If it is not possible to transport most of the water from the original tank, or if the chemistry reading of the water taken when installing the new tank is not ideal, it may be necessary to allow time for the new tank cycled before inserting the discus fish.

To speed up the process, add live bacteria to the tank and monitor ammonia levels to track the nitrogen cycle as it begins.

During the time it takes to cycle the tank, it is essential to keep the water quality in the discus fish containers high.

Install a filter or at least one air stone in each bucket to maintain water circulation and make routine water changes.

It may also be necessary to install a submersible heater in each bucket to keep the water temperature stable.

If there is not enough equipment available to install in each of the buckets, it may be necessary to consolidate some of the fish in the largest available containers.

Keeping Male And Female Discus Fish Together

As a species, discus fish are generally peaceful and somewhat shy. These fish thrive better in groups of three or more and generally do well regardless of how many males or females are part of the group.

However, in some cases, males of the species can become aggressive, which could cause problems in the discus tank. In most cases, an aggressive male fish will direct most of its aggression towards a smaller or weaker male fish, but during breeding or spawning, this behavior can be directed at any discus fish that gets too close.

For breeding, discus fish are best kept in pairs that consist of a male and a female or trios consisting of two females and one male.

During the early stages of the breeding process, it is likely that both the male and female discus fish in the breeding pair will become protectors of a certain area in the tank they have chosen to spawn. The breeding couple defends this area against other discus fish, both male and female.

When a breeding pair is established in the aquarium, it is not wise to keep another discus fish, in particular, a male discus, in the same tank.