Can Cockatoo Dwarf Cichlid and Rummy-Nose Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Possible with Caution

Keeping Cockatoo Dwarf Cichlid and Rummy-Nose Tetra together is possible but requires caution due to differing aggression levels and potential behavioral clashes. Provide a spacious tank of at least 75 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Cockatoo Dwarf Cichlid

Apistogramma cacatuoides

Rummy-Nose Tetra

Hemigrammus rhodostomus

🐠Family Group
Cockatoo Dwarf Cichlid
Cichlids - South American
Rummy-Nose Tetra
Characins
Temperament
Cockatoo Dwarf Cichlid
Semi-Aggressive (5/10)
Rummy-Nose Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Cockatoo Dwarf Cichlid
24–28°C
Rummy-Nose Tetra
24–28°C
pH Range
✓ Compatible
Cockatoo Dwarf Cichlid
6–7.5
Rummy-Nose Tetra
5.5–7
Hardness (dGH)
✓ Compatible
Cockatoo Dwarf Cichlid
2–10
Rummy-Nose Tetra
1–12
Water Type
✓ Compatible
Cockatoo Dwarf Cichlid
Freshwater Only
Rummy-Nose Tetra
Freshwater Only
Flow Preference
✓ Compatible
Cockatoo Dwarf Cichlid
Low
Rummy-Nose Tetra
Moderate
Min Tank Volume
Combined: 75 L
Cockatoo Dwarf Cichlid
60 L
Rummy-Nose Tetra
75 L
Swimming Level
Shared: 1 zone
Cockatoo Dwarf Cichlid
Bottom
Rummy-Nose Tetra
MiddleBottom
🏷️Behavior Tags
Cockatoo Dwarf Cichlid
Territorial (Defends specific area)Fry PredatorShrimp Eater
Rummy-Nose Tetra
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Fry PredatorNano / Bite-sized (Predation Risk)
Stocking calculator

Can your tank handle Cockatoo Dwarf Cichlid and Rummy-Nose Tetra?

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.

Cockatoo Dwarf Cichlid
Rummy-Nose Tetra
Test both in my tank

Behaviour & Temperament

Cockatoo Dwarf Cichlid is a moderately assertive species (5/10), while Rummy-Nose Tetra is peaceful (1/10). This notable difference means Cockatoo Dwarf Cichlid may occasionally assert dominance over Rummy-Nose Tetra.

Cockatoo Dwarf Cichlid and Rummy-Nose Tetra both frequent the 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: Shrimp eaters may also prey on very small nano fish.

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 Cockatoo Dwarf Cichlid and Rummy-Nose Tetra to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Cockatoo Dwarf Cichlid and Rummy-Nose Tetra together, plan for an aquarium of at least 75 litres with a minimum length of 75 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 — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Densely covered, Plants - lighly covered. 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 Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Cockatoo Dwarf Cichlid and Rummy-Nose Tetra need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Cockatoo Dwarf Cichlid and Rummy-Nose Tetra.

Show 15 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Cockatoo Dwarf Cichlid is a known shrimp eater and may prey on small invertebrates or nano fish like Rummy-Nose Tetra.

Frequently Asked Questions

Can Cockatoo Dwarf Cichlid and Rummy-Nose Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 75 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Cockatoo Dwarf Cichlid and Rummy-Nose Tetra need?

A minimum of 75 litres (tank length at least 75 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 Cockatoo Dwarf Cichlid and Rummy-Nose Tetra together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Cockatoo Dwarf Cichlid or Rummy-Nose Tetra aggressive?

Cockatoo Dwarf Cichlid is moderately assertive (5/10) and Rummy-Nose Tetra is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Cockatoo Dwarf Cichlid and Rummy-Nose Tetra need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Cockatoo Dwarf Cichlid's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Cockatoo Dwarf Cichlid 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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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