Discussing Discus Dynamics
There is no denying that discus are viewed as a show stopper, even among individuals who don’t own aquariums. We have our 150 gallon (568 L) discus aquarium positioned at the entrance of our home. Everyone we greet at the door can’t help but stare transfixed by the aquarium for a few moments. While these aquatic beauties are eye catching, they do entail their own unique requirements. In the past, we have discussed the equipment running our system and the maintenance we conduct on the tank. However, this article will focus on describing discus. We will be highlighting their physical attributes, housing requirements & our own personal anecdotal observation of behavioral tendencies.
Size: Fully grown discus can reach a size of 7 inches (18 cm) or more
Life Span: 7 to 8 years. Though there are “fish tales” of discus living for 10+ years. Poor husbandry will dramatically shorten their life expectancy
Appearance: Discus should have a round shape from which it derives its name. When viewing head on, their forehead should not appear pinched nor should their abdomen region. Fins should not be clamped, but outstretched. Discus fish which are dark in coloring are typically stressed.
Cichlid Fish: Discus belong to the family Cichlidae, commonly referred to as cichlids. Just like breed knowledge is important when selecting a puppy, understanding the fish family is crucial for aquatic success. As with many cichlids, discus exhibit intelligent behavior, intricate courtship practices, rearing responsibilities & aggressive tendencies.
Group Mentality: School is in session for these fish! Discus are shoaling fish, meaning they obtain security and socialize among a group of other discus. For this reason it is strongly encouraged to keep discus in a group of 6 or more. Additionally, larger groups will help to alleviate aggression among individuals. Remember discus are cichlid fish and can at times show aggression towards their own kind. Maintaining a larger group of discus permits members to distribute a slight peck here or there without one member being persistently picked upon. Most of the aggression witnessed within our tank was due to establishing a pecking order. Discus kept in small groups frequently witness one member constantly bullied by the more dominant discus.
Minimum Tank Size: 55 gallons & that is the bare minimum. However, this is one of those cases where bigger is better. Let’s face it, you like big fish that’s why you are reading about discus and not minnows. So get your big fish a big home. Preferably, we recommend starting within the 65 to 75 gallon range, but I would buy as much tank as your budget and interior space allows. Remember discus do best in groups of 6 or more and you typically want to allocate 10 gallons of space per fish.
Temperature Range: 82 - 86F (28 - 30 C)
Some sources will tell you that the ideal pH for discus is 6 and to never allow levels to rise above 7. However, we have found that consistency is key. The average pH of our tank runs around 8. The most detrimental occurrence for any fish, not just exclusively discus, is to experience pH swings. Rather than constantly fighting to keep the pH levels lower in our tank, we choose to keep the levels stable and have witnessed no ill effects towards our fish. Many have reported keeping healthy, happy discus for years within elevated pH levels.
Tankmates: Many discus hobbyists choose to keep exclusively discus aquariums. However, many fish are compatible with discus if you are seeking a little diversity within your aquarium. Some things to keep in mind when selecting tankmates:
Fish frequently paired with discus include: Rummy-Nose, Cardinals & Lemon tetra. Personally, we choose to include cardinals and rummy-nose tetra within our aquarium and greatly enjoy the schooling behavior of these fish. Rams (German Blue, Electric Blue, Golden & Bolivian Rams) also make suitable tankmates. In regards to clean-up crew many rely upon bristlenose catfish (Ancistrus), amano shrimp (could potentially become lunch), schools of cory and otocinclus catfish (otos). We’ve attempted to keep otos within our discus tank before; however, they rarely made it past the 6 month mark. They would make it through their quarantine period safely, but never last more than a few months within the discus tank. We suspect that the higher temperatures might affect their lifespan. It should also be noted that some have reported otos attaching to discus to eat away at their slime coat. Though we never witnessed this aggressive behavior within our tank; should you choose to add otos, observe the fish to insure that there is no threat towards your discus.
We introduced the angelfish into our discus tank early into our stocking process. At the time, the 150 gallon tank housed a total of 5 discus. The two angelfish had gone through a quarantine period where they were carefully observed and treated for any potential pathogens which could be passed along to the discus. When the angelfish were added, the discus were significantly larger than the angelfish and had been housed within the aquarium for 2 months preceding the angelfish introduction. The angelfish’s diminutive size, coming into an established territory and being outnumbered have potentially aided our peaceful arrangement. Additionally, the angelfish are not a mated pair so there is no hostility which could potentially arise during angelfish spawning. With all that said, it should be noted that our aquarium arrangement is only one data point. Many have reported experiencing issues surrounding housing discus and angelfish together. Should you decided to attempt the endeavor, please follow strict quarantine procedures and observe all fish during introduction. For all fish introduced with discus, not exclusively angelfish, be prepared to remove & re-home fish that present a danger to each other.
Food Selection: As with all fish, a varied diet generates healthy fish. However, for discus our staple meal is beefheart. Beefheart is extremely high in protein which provides growing discus with the nutrients they need. We generate our own beefheart mixture roughly every three months and freeze the prepared meals. In the future, we plan to post information surrounding the exact ingredients and steps we utilize for our beefheart mixture. Other meals to consider for a discus diet include frozen bloodworms (we use Hikari) & dried pellets (we use Colbalt Discus Flakes & TetraColor Tropical Granules).
Feeding Frequency: Our adult discus receive meals twice daily. However if you are growing young discus, it is much better to feed multiple smaller meals throughout the day. Remember underfed discus can become stunted.
Moonlights: When we initially set up our discus aquarium, we did not have moonlights above the aquarium. We found at night the discus became extremely jumpy. The slightest shadow would cause splashing and mad darting across the aquarium. To rectify the issue, we placed a strip of moonlight across the top. Since the installation of the moonlights, we have not observed the discus become startled with outside tank movements.
Skittish Nature: Some within the hobby have advised against placing a discus aquarium within a high traffic area since they can be skittish by nature. We have our aquarium located within the entryway of our home. We frequent this area daily as we come and go. This location, as you can imagine, also receives a lot of activity as we welcome guests into our home. We have not witnessed any ill effects towards the fish within this location. Many are enamored with the aquarium when they first arrive and instantly approach the glass for a closer look. All of our fish eagerly swim up to meet the guest (in hopes of meal I presume). However, we do provide coverage areas in the corners of the tank with decorative plants so the discus have a place to withdraw should they feel the need to hide in order to feel secure. Make sure to include hiding areas within your aquarium.
Discus are a joy to watch and own. Nothing beats a stressful day at work better than just watching these ethereal creatures seamlessly float through the water. Overtime, you get to observe their unique personalities and discover that they are very different from many other freshwater fish. Their presence does require additional maintenance not necessary for other freshwater aquariums. If you are considering keeping discus, please take the time to read through our maintenance schedule in order to help you determine if you have the time necessary to dedicate to these fish. While demanding, these creatures are more than worth the effort. Additionally, for those considering discus: I would strongly recommend visiting Simply Discus. The site has a plethora of information dedicated strictly to discus keeping for both the beginner and advanced aquarist. They also have a wonderful community forum who are happy to offer advise and their own observations on discus fish. We would not have experienced as much success with our aquarium if it was not for this resource.