Can Siamese Algae Eater and True Julii Corydoras Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 1, 2026
Possible with Caution

Keeping Siamese Algae Eater and True Julii Corydoras together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 110 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Siamese Algae Eater

Crossocheilus oblongus

True Julii Corydoras

Corydoras julii

🐠Family Group
Siamese Algae Eater
Cyprinids
True Julii Corydoras
Catfish
Temperament
Siamese Algae Eater
Mostly Peaceful (3/10)
True Julii Corydoras
Peaceful (0/10)
Temperature
✓ Compatible
Siamese Algae Eater
22–28°C
True Julii Corydoras
23–26°C
pH Range
✓ Compatible
Siamese Algae Eater
6–7.5
True Julii Corydoras
6–7.5
Hardness (dGH)
✓ Compatible
Siamese Algae Eater
5–15
True Julii Corydoras
2–15
Water Type
✓ Compatible
Siamese Algae Eater
Freshwater Only
True Julii Corydoras
Freshwater Only
Flow Preference
✓ Compatible
Siamese Algae Eater
Moderate
True Julii Corydoras
Moderate
Min Tank Volume
Combined: 110 L
Siamese Algae Eater
110 L
True Julii Corydoras
60 L
Swimming Level
Shared: 1 zone
Siamese Algae Eater
BottomMiddle
True Julii Corydoras
Bottom
🏷️Behavior Tags
Siamese Algae Eater
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)Territorial (Defends specific area)
True Julii Corydoras
Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Siamese Algae Eater and True Julii Corydoras?

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.

Siamese Algae Eater
True Julii Corydoras
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Behaviour & Temperament

Siamese Algae Eater is a generally mild-mannered species (3/10), while True Julii Corydoras is peaceful (0/10). This modest difference means Siamese Algae Eater may occasionally assert dominance over True Julii Corydoras.

Siamese Algae Eater and True Julii Corydoras 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.

Worth noting: Siamese Algae Eater is a known jumper, so a tight-fitting lid is essential.

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 Siamese Algae Eater and True Julii Corydoras to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

Water Parameters

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Siamese Algae Eater and True Julii Corydoras together, plan for an aquarium of at least 110 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 — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Established Algae (Otocinclus), Driftwood (Digestion/Hiding), Plants - lighly covered, Sand (Sifters). 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.

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. Siamese Algae Eater and True Julii Corydoras 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 Siamese Algae Eater and True Julii Corydoras.

Show 10 more tank sizes

Frequently Asked Questions

Can Siamese Algae Eater and True Julii Corydoras live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 110 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Siamese Algae Eater and True Julii Corydoras need?

A minimum of 110 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 Siamese Algae Eater and True Julii Corydoras together?

Keep the aquarium between 23°C and 26°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Siamese Algae Eater or True Julii Corydoras aggressive?

Siamese Algae Eater is generally mild-mannered (3/10) and True Julii Corydoras is peaceful (0/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Siamese Algae Eater and True Julii Corydoras need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Siamese Algae Eater's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Siamese Algae Eater 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 1, 2026
Last updated
May 1, 2026
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