Can Banded Archerfish (Brackish) and Jack Dempsey Live Together?

🔴Not Recommended

Banded Archerfish (Brackish) and Jack Dempsey are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Banded Archerfish (Brackish)

Toxotes jaculatrix

Jack Dempsey

Rocio octofasciata

🐠Family Group
Banded Archerfish (Brackish)
Oddballs
Jack Dempsey
Cichlids - Central American
Temperament
Banded Archerfish (Brackish)
Semi-Aggressive (6/10)
Jack Dempsey
Aggressive (8/10)
Temperature
✓ Compatible
Banded Archerfish (Brackish)
24–30°C
Jack Dempsey
22–30°C
pH Range
✓ Compatible
Banded Archerfish (Brackish)
7–8.5
Jack Dempsey
6.5–8
Hardness (dGH)
✓ Compatible
Banded Archerfish (Brackish)
15–30
Jack Dempsey
5–15
Water Type
✗ No overlap
Banded Archerfish (Brackish)
Brackish Required
Jack Dempsey
Freshwater Only
Flow Preference
✓ Compatible
Banded Archerfish (Brackish)
Moderate
Jack Dempsey
Moderate
Min Tank Volume
Combined: 360 L
Banded Archerfish (Brackish)
300 L
Jack Dempsey
200 L
Swimming Level
✓ Different zones
Banded Archerfish (Brackish)
Top
Jack Dempsey
MiddleBottom
🏷️Behavior Tags
Banded Archerfish (Brackish)
Piscivore (Eats small/nano fish)Jumper (Lid Required)Hyperactive / Fast SwimmerAggressive to same species/look-alikes
Jack Dempsey
Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)Plant Destroyer

Behaviour & Temperament

Banded Archerfish (Brackish) is a moderately assertive species (6/10), while Jack Dempsey is semi-aggressive (8/10). This modest difference means Jack Dempsey may occasionally assert dominance over Banded Archerfish (Brackish).

In terms of spatial distribution, Banded Archerfish (Brackish) prefers the Top (Surface) zone, whereas Jack Dempsey occupies the Middle (Open Water) and Bottom (Substrate) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Banded Archerfish (Brackish) is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 30°C. Aim for the midpoint of this range (around 27.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

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

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Banded Archerfish (Brackish) and Jack Dempsey together, plan for an aquarium of at least 360 litres with a minimum length of 120 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), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). 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.

Frequently Asked Questions

Can Banded Archerfish (Brackish) and Jack Dempsey live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Banded Archerfish (Brackish) and Jack Dempsey need?

A minimum of 360 litres (tank length at least 120 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 Banded Archerfish (Brackish) and Jack Dempsey together?

Keep the aquarium between 24°C and 30°C. A target of around 27.0°C sits comfortably within both species' preferred ranges.

Are Banded Archerfish (Brackish) or Jack Dempsey aggressive?

Banded Archerfish (Brackish) is moderately assertive (6/10) and Jack Dempsey is semi-aggressive (8/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Banded Archerfish (Brackish) and Jack Dempsey need?

Both species overlap in the 7–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Jack Dempsey's territorial behaviour?

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


Related Comparisons