Can Knight Goby and Port Acara Live Together?

Possible with Caution

Keeping Knight Goby and Port Acara together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 150 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Knight Goby

Stigmatogobius sadanundio

Port Acara

Cichlasoma portalegrense

🐠Family Group
Knight Goby
Gobies & Gudgeons
Port Acara
Cichlids - South American
Temperament
Knight Goby
Semi-Aggressive (6/10)
Port Acara
Semi-Aggressive (5/10)
Temperature
βœ“ Compatible
Knight Goby
20–28Β°C
Port Acara
22–28Β°C
pH Range
βœ“ Compatible
Knight Goby
7–8.5
Port Acara
6–7.5
Hardness (dGH)
βœ“ Compatible
Knight Goby
10–30
Port Acara
3–15
Water Type
βœ“ Compatible
Knight Goby
Brackish Tolerant
Port Acara
Freshwater Only
Flow Preference
βœ“ Compatible
Knight Goby
Moderate
Port Acara
Low
Min Tank Volume
Combined: 150 L
Knight Goby
75 L
Port Acara
150 L
Swimming Level
Shared: 2 zones
Knight Goby
MiddleBottom
Port Acara
MiddleBottom
🏷️Behavior Tags
Knight Goby
Fin NipperShrimp EaterFry PredatorTerritorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Port Acara
Digger (Disturbs Substrate)Territorial (Defends specific area)Fry Predator
Stocking calculator

Can your tank handle Knight Goby and Port Acara?

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.

Knight Goby
Port Acara
Test both in my tank

Behaviour & Temperament

Knight Goby is a moderately assertive species (6/10), while Port Acara is moderately assertive (5/10). This modest difference means Knight Goby may occasionally assert dominance over Port Acara.

Knight Goby and Port Acara 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: Two territorial species may clash over territory, especially in smaller tanks.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Knight Goby and Port Acara to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 22Β°C and 28Β°C. Aim for the midpoint of this range (around 25.0Β°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Knight Goby and Port Acara together, plan for an aquarium of at least 150 litres with a minimum length of 90 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots β€” caves, driftwood, and dense plant clusters β€” so the less dominant fish can retreat when needed.

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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Knight Goby and Port Acara.

Show 9 more tank sizes

Frequently Asked Questions

Can Knight Goby and Port Acara live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 150 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Knight Goby and Port Acara need?

A minimum of 150 litres (tank length at least 90 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 Port Acara together?

Keep the aquarium between 22Β°C and 28Β°C. A target of around 25.0Β°C sits comfortably within both species' preferred ranges.

Are Knight Goby or Port Acara aggressive?

Knight Goby is moderately assertive (6/10) and Port Acara is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Knight Goby and Port Acara need?

Both species overlap in the 7–7.5 pH range. Consistency is key β€” avoid sudden swings, and test regularly to stay within this window.

Will Knight Goby nip Port Acara's fins?

Knight Goby is a known fin nipper. If Port Acara 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 dΓ©cor that divides the tank into distinct zones works especially well.


Related Comparisons