Can Gardner's Killifish and Neolamprologus Similis Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Gardner's Killifish and Neolamprologus Similis 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

Gardner's Killifish

Fundulopanchax gardneri

Neolamprologus Similis

Neolamprologus similis

🐠Family Group
Gardner's Killifish
Killifish
Neolamprologus Similis
Cichlids - African
Temperament
Gardner's Killifish
Mostly Peaceful (4/10)
Neolamprologus Similis
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Gardner's Killifish
20–26°C
Neolamprologus Similis
24–27°C
pH Range
✗ No overlap
Gardner's Killifish
6–7.5
Neolamprologus Similis
7.8–9
Hardness (dGH)
✓ Compatible
Gardner's Killifish
4–10
Neolamprologus Similis
10–25
Water Type
✓ Compatible
Gardner's Killifish
Freshwater Only
Neolamprologus Similis
Freshwater Only
Flow Preference
✓ Compatible
Gardner's Killifish
Low
Neolamprologus Similis
Moderate
Min Tank Volume
Combined: 38 L
Gardner's Killifish
38 L
Neolamprologus Similis
38 L
Swimming Level
✓ Different zones
Gardner's Killifish
TopMiddle
Neolamprologus Similis
Bottom
🏷️Behavior Tags
Gardner's Killifish
Jumper (Lid Required)Fry PredatorShrimp EaterHyperactive / Fast Swimmer
Neolamprologus Similis
Nano / Bite-sized (Predation Risk)Territorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Stocking calculator

Can your tank handle Gardner's Killifish and Neolamprologus Similis?

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.

Gardner's Killifish
Neolamprologus Similis
Test both in my tank

Behaviour & Temperament

Gardner's Killifish is a generally mild-mannered species (4/10), while Neolamprologus Similis is moderately assertive (6/10). This modest difference means Neolamprologus Similis may occasionally assert dominance over Gardner's Killifish.

In terms of spatial distribution, Gardner's Killifish prefers the Top (Surface) and Middle (Open Water) zones, whereas Neolamprologus Similis occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Gardner's Killifish 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 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Gardner's Killifish (6–7.5) and Neolamprologus Similis (7.8–9) do not overlap, making it impossible to satisfy both species simultaneously.

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

Tank Setup

To house Gardner's Killifish and Neolamprologus Similis together, plan for an aquarium of at least 38 litres with a minimum length of 45 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: Plants - Densely covered, Plants - Floating, Plants - lighly covered, Sand (Sifters), Shells (Breeding/Hiding). 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

Gardner's Killifish and Neolamprologus Similis 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 Gardner's Killifish and Neolamprologus Similis.

Show 22 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Gardner's Killifish is a known shrimp eater and may prey on small invertebrates or nano fish like Neolamprologus Similis.

Frequently Asked Questions

Can Gardner's Killifish and Neolamprologus Similis live together?

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

What size tank do Gardner's Killifish and Neolamprologus Similis need?

A minimum of 38 litres (tank length at least 45 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 Gardner's Killifish and Neolamprologus Similis together?

Keep the aquarium between 24°C and 26°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Gardner's Killifish or Neolamprologus Similis aggressive?

Gardner's Killifish is generally mild-mannered (4/10) and Neolamprologus Similis is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Gardner's Killifish and Neolamprologus Similis need?

Their pH requirements do not overlap. Gardner's Killifish prefers 6–7.5, while Neolamprologus Similis needs 7.8–9. This makes them incompatible in the same water chemistry.

How do I manage Neolamprologus Similis's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Neolamprologus Similis 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 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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