How Many Discus Fish Can Be in A Tank

Discus fish are one of the most beautiful tropical fish. Circular bodies, large size, and bright color tend to make aquarists think about Discus fish stocking ideas. This king of the aquarium belongs to the cichlids’ family. Discus fish stocking density depends on several parameters, i.e., size, water requirements, etc.

This article will address size variation, and grouping, and discuss fish stoking tips. Moreover, you’ll also learn about how many Discus fish you can keep in a 75-gallon tank before the last section.

discus fish stocking ideas

Discus Fish Sizes

There are about three main species of discus fish.

Symphysodon aequifasciatus Pellegrin: Blue Discus or brown Discus
Symphysodon discus Heckel: Red Discus or Heckel Discus
Symphysodon tarzoo E. Lyons: Green Discus

They have numerous types. These types vary in color pattern, size, etc. The discus size varies between 1.5 inches to 12 inches. Although, the upper size threshold is rare. However, you can find 10-inch-long Discus fish. In the following, different types are discussed relative to their size.

Type Size (inches) Type Size (inches)
Red Discus 4.8–6.0 Blue Discus 2.5–3.0
Green Discus 8-12 Brown Discus 6
Heckel Cross Discus 5-6 White Butterfly Discus 6
Ghost Discus 6-8 Albino Golden Discus 8–12
Albino Platinum Discus 8–12 Pigeon Blood Discus 6-7
Blue Scorpion Discus 6-6.5 Albino Millennium Gold 8–12
White Diamond Discus 6-7 Cobalt Blue Discus 8-10
Golden Calico Discus 3-5 White Dragon Discus 4.8–6.0

How Many Discus Fish Should Be Kept Together

Contrary to many other fish, Discus fish feel stress and other behavioral changes, i.e., aggression, loss of weight, etc., on stocking alone. Therefore, stocking them in a group is recommended. Here are some about Discus fish stocking density and other rules for setting up a new tank.

Discus Density

A group should include at least 3 Discus fish. However, it’s optimal to introduce it in a group of 5 fish.

Other Rules

Here are some other Discus fish stocking density rules that will help to make a successful Discus tank.

  • They should stock larger tanks, i.e., at least 50-gallon tanks.
  • There should be the minimum decorations in a tank, i.e., they are active swimmers.
  • While stocking with other fish, remember the size, temperament, and feeding habits of other fish.
  • Keep the tank water clean and optimum because they are sensitive to water quality.
  • Keep an eye on their behavior for proper care.

How Many Discus Fish in a 75-Gallon Tank

Discus fish are free swimmers and have social behavior. They love to live in groups. Therefore, a big tank is the most suitable. 75- gallons is the most common tank used for discus fish stocking. Keep 1 discus fish per 10-gallon water. So, you can keep 6 or 7 discus fish in your 75-gallon tank.

discus fish stocking density

Discus Fish Stocking Tips

Here are some more discus fish stocking tips. These tips will help you to set up an ideal discus tank.

Tank Size

Discus fish are schooling and require a large tank. Therefore, it’s optimal to stock them in at least a 55-gallon tank. However, a 75-gallon tank is more common and suitable with a 3 ft long, 1.5 ft high, and 1 ft wide dimension. A general rule for Discus fish stocking is to keep 1 fish per 10 gallons at least.

Water Quality

Discus fish is a freshwater habitat. Therefore, keep the proper water parameters for optimal growth. Moreover, always keep the water clean and avoid temperature fluctuation. Temperature fluctuation can cause shock to fish. Here are the water parameters.

pH: 5.0-7.0 Total Hardness: 1-4°dKH Temperature: 82-84°F


You can introduce broadleaf plants in your Discus fish tank. Discus fish use the plant leaves as hiding spots. Driftwood is also appreciative. The suitable plant options are the following.

Pogostemon Octopus Dwarf Aquarium Lily
Java Fern Tiger Lotus

Suitable Tank Mates

Discus fish are peaceful creatures. You can stock them with the same temperament companions. Here are some suitable companions.

Cardinals Pencilfish Tetras Rummy Nose
Ottos Silver Tip Marbled Hatchetfish


Discus fish are active and free swimmers. Therefore, it’s not suitable to unnecessarily fill the tank with decoration. Moreover, they also don’t like too much light and noise. A 2-5 watt aquarium light per gallon is the most suitable option.

How many discus fish


Another discus fish stocking idea is to quarantine them in a well-established tank to avoid catastrophe. This quarantine duration is 1 month or 6 weeks. It’ll help them to adjust according to the tank’s condition and treatment in case of any disease.


Discus fish are omnivores, which means they eat a variety of food. Their diet includes plant material, small crustaceans, residue, and worms. Moreover, you can also feed them over processed food, i.e., pellets, fish flakes, live and frozen food. The food should contain protein 35 to 40% for adults and 50% for young ones.


Don’t use black color. It’s best to go with a sky-blue or white color for discus. These colors will elevate the overall look of the tank.


Use a fish tank filter that filters all volumes at least 3 times per hour.

Final Thoughts

Keeping 1 tropical king, i.e., discus fish, per 10-gallon is a rule of thumb for stoking discus fish. Moreover, the stocking depends on many other parameters, i.e., type, size, feeding requirements, and color choice. 75-gallon tanks with a daily water change, low-lighting, and many other discus fish stocking tips are the most common and ideal.

Related Products

hygger LED Fish Tank Lights
hygger Fish Tank Lights DIY Mode

hygger LED Fish Tank Lights

hygger Quartz Tube Aquarium Heater
Quartz tube heater controller

hygger Quartz Tube Aquarium Heater


Leave a Comment

Your email address will not be published.