Can Knight Goby and Uaru Live Together?

🔴Not Recommended

Knight Goby and Uaru are not recommended as tank mates due to incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Knight Goby

Stigmatogobius sadanundio

Uaru

Uaru amphiacanthoides

🐠Family Group
Knight Goby
Gobies & Gudgeons
Uaru
Cichlids - South American
Temperament
Knight Goby
Semi-Aggressive (6/10)
Uaru
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Knight Goby
20–28°C
Uaru
27–30°C
pH Range
✓ Compatible
Knight Goby
7–8.5
Uaru
5–7
Hardness (dGH)
✗ No overlap
Knight Goby
10–30
Uaru
1–8
Water Type
✓ Compatible
Knight Goby
Brackish Tolerant
Uaru
Freshwater Only
Flow Preference
✓ Compatible
Knight Goby
Moderate
Uaru
Low
Min Tank Volume
Combined: 480 L
Knight Goby
75 L
Uaru
400 L
Swimming Level
Shared: 2 zones
Knight Goby
MiddleBottom
Uaru
MiddleBottom
🏷️Behavior Tags
Knight Goby
Fin NipperShrimp EaterFry PredatorTerritorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Uaru
Plant DestroyerShy / Slow Moving (Easily Stressed)Shrimp Eater

Behaviour & Temperament

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

Knight Goby and Uaru 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.

Water Parameters

The safe temperature window for both species falls between 27°C and 28°C. Aim for the midpoint of this range (around 27.5°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Knight Goby needs 10–30 dGH while Uaru requires 1–8 dGH. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Knight Goby and Uaru together, plan for an aquarium of at least 480 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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), Shells (Breeding/Hiding), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

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

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Knight Goby and Uaru live together?

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

What size tank do Knight Goby and Uaru need?

A minimum of 480 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 Knight Goby and Uaru together?

Keep the aquarium between 27°C and 28°C. A target of around 27.5°C sits comfortably within both species' preferred ranges.

Are Knight Goby or Uaru aggressive?

Knight Goby is moderately assertive (6/10) and Uaru is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Knight Goby and Uaru need?

Both species overlap in the 7–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Knight Goby nip Uaru's fins?

Knight Goby is a known fin nipper. If Uaru has long or flowing fins, there is a real risk of fin damage. Keeping Knight Goby in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Knight Goby's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Knight Goby 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.


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