Can Cobalt Blue Zebra and Siamese Algae Eater Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 3, 2026
Not Recommended

Cobalt Blue Zebra and Siamese Algae Eater 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

Cobalt Blue Zebra

Metriaclima callainos

Siamese Algae Eater

Crossocheilus oblongus

🐠Family Group
Cobalt Blue Zebra
Cichlids - African
Siamese Algae Eater
Cyprinids
Temperament
Cobalt Blue Zebra
Aggressive (8/10)
Siamese Algae Eater
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Cobalt Blue Zebra
24–28°C
Siamese Algae Eater
22–28°C
pH Range
✗ No overlap
Cobalt Blue Zebra
7.8–8.6
Siamese Algae Eater
6–7.5
Hardness (dGH)
✓ Compatible
Cobalt Blue Zebra
10–25
Siamese Algae Eater
5–15
Water Type
✓ Compatible
Cobalt Blue Zebra
Freshwater Only
Siamese Algae Eater
Freshwater Only
Flow Preference
✓ Compatible
Cobalt Blue Zebra
Moderate
Siamese Algae Eater
Moderate
Min Tank Volume
Combined: 200 L
Cobalt Blue Zebra
200 L
Siamese Algae Eater
110 L
Swimming Level
Shared: 2 zones
Cobalt Blue Zebra
MiddleBottom
Siamese Algae Eater
BottomMiddle
🏷️Behavior Tags
Cobalt Blue Zebra
Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Hyperactive / Fast SwimmerDigger (Disturbs Substrate)Plant Destroyer
Siamese Algae Eater
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)Territorial (Defends specific area)
Stocking calculator

Can your tank handle Cobalt Blue Zebra and Siamese Algae Eater?

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.

Cobalt Blue Zebra
Siamese Algae Eater
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Behaviour & Temperament

Cobalt Blue Zebra is a semi-aggressive species (8/10), while Siamese Algae Eater is generally mild-mannered (3/10). This notable difference means Cobalt Blue Zebra may occasionally assert dominance over Siamese Algae Eater.

Cobalt Blue Zebra and Siamese Algae Eater 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.

Worth noting: Siamese Algae Eater 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Cobalt Blue Zebra (7.8–8.6) and Siamese Algae Eater (6–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

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

Tank Setup

To house Cobalt Blue Zebra and Siamese Algae Eater together, plan for an aquarium of at least 200 litres with a minimum length of 120 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: Sand (Sifters), Established Algae (Otocinclus), Driftwood (Digestion/Hiding), Plants - lighly covered. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Cobalt Blue Zebra is a plant destroyer, which conflicts with Siamese Algae Eater's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Why This Pairing Usually Fails in Practice

Cobalt Blue Zebra and Siamese Algae Eater 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 Cobalt Blue Zebra and Siamese Algae Eater.

Show 5 more tank sizes

Frequently Asked Questions

Can Cobalt Blue Zebra and Siamese Algae Eater live together?

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

What size tank do Cobalt Blue Zebra and Siamese Algae Eater need?

A minimum of 200 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 Cobalt Blue Zebra and Siamese Algae Eater 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 Cobalt Blue Zebra or Siamese Algae Eater aggressive?

Cobalt Blue Zebra is semi-aggressive (8/10) and Siamese Algae Eater is generally mild-mannered (3/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Cobalt Blue Zebra and Siamese Algae Eater need?

Their pH requirements do not overlap. Cobalt Blue Zebra prefers 7.8–8.6, while Siamese Algae Eater needs 6–7.5. This makes them incompatible in the same water chemistry.

How do I manage Cobalt Blue Zebra's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Cobalt Blue Zebra 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 3, 2026
Last updated
May 3, 2026
Issues or corrections?
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