Can Discus and Sunset Hap Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Discus and Sunset Hap are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Discus

Symphysodon aequifasciatus

Sunset Hap

Dimidiochromis strigatus

🐠Family Group
Discus
Cichlids - South American
Sunset Hap
Cichlids - African
Temperament
Discus
Mostly Peaceful (4/10)
Sunset Hap
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Discus
28–32°C
Sunset Hap
24–28°C
pH Range
✗ No overlap
Discus
5–7.5
Sunset Hap
7.6–8.6
Hardness (dGH)
✓ Compatible
Discus
1–12
Sunset Hap
10–25
Water Type
✓ Compatible
Discus
Freshwater Only
Sunset Hap
Freshwater Only
Flow Preference
✓ Compatible
Discus
Low
Sunset Hap
Moderate
Min Tank Volume
Combined: 408 L
Discus
250 L
Sunset Hap
400 L
Swimming Level
Shared: 2 zones
Discus
MiddleBottom
Sunset Hap
MiddleBottom
🏷️Behavior Tags
Discus
Shy / Slow Moving (Easily Stressed)Territorial (Defends specific area)Aggressive to same species/look-alikesShrimp Eater
Sunset Hap
Piscivore (Eats small/nano fish)Aggressive to same species/look-alikesHyperactive / Fast SwimmerTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Discus and Sunset Hap?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Discus
Sunset Hap
Test both in my tank

Behaviour & Temperament

Discus is a generally mild-mannered species (4/10), while Sunset Hap is moderately assertive (6/10). This modest difference means Sunset Hap may occasionally assert dominance over Discus.

Discus and Sunset Hap both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Two territorial species may clash over territory, especially in smaller tanks.

Water Parameters

The safe temperature window for both species falls between 28°C and 28°C. Aim for the midpoint of this range (around 28.0°C) for optimal comfort.

The pH requirements of Discus (5–7.5) and Sunset Hap (7.6–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Discus and Sunset Hap together, plan for an aquarium of at least 408 litres with a minimum length of 150 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Usually Fails in Practice

Discus and Sunset Hap are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Discus and Sunset Hap.

Frequently Asked Questions

Can Discus and Sunset Hap live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Discus and Sunset Hap need?

A minimum of 408 litres (tank length at least 150 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Discus and Sunset Hap together?

Keep the aquarium between 28°C and 28°C. A target of around 28.0°C sits comfortably within both species' preferred ranges.

Are Discus or Sunset Hap aggressive?

Discus is generally mild-mannered (4/10) and Sunset Hap is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Discus and Sunset Hap need?

Their pH requirements do not overlap. Discus prefers 5–7.5, while Sunset Hap needs 7.6–8.6. This makes them incompatible in the same water chemistry.

How do I manage Discus's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Discus space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
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