Can Black Fin Cory and Bolivian Ram Live Together?

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

Keeping Black Fin Cory and Bolivian Ram together is possible but requires caution, though some care is needed. 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

Black Fin Cory

Corydoras leucomelas

Bolivian Ram

Mikrogeophagus altispinosus

🐠Family Group
Black Fin Cory
Catfish
Bolivian Ram
Cichlids - South American
Temperament
Black Fin Cory
Peaceful (1/10)
Bolivian Ram
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Black Fin Cory
22–26°C
Bolivian Ram
23–28°C
pH Range
✓ Compatible
Black Fin Cory
6–7.5
Bolivian Ram
6–7.5
Hardness (dGH)
✓ Compatible
Black Fin Cory
2–15
Bolivian Ram
2–10
Water Type
✓ Compatible
Black Fin Cory
Freshwater Only
Bolivian Ram
Freshwater Only
Flow Preference
✓ Compatible
Black Fin Cory
Low
Bolivian Ram
Low
Min Tank Volume
Combined: 75 L
Black Fin Cory
75 L
Bolivian Ram
75 L
Swimming Level
Shared: 1 zone
Black Fin Cory
Bottom
Bolivian Ram
BottomMiddle
🏷️Behavior Tags
Black Fin Cory
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)
Bolivian Ram
Digger (Disturbs Substrate)Territorial (Defends specific area)
Stocking calculator

Can your tank handle Black Fin Cory and Bolivian Ram?

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.

Black Fin Cory
Bolivian Ram
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Behaviour & Temperament

Black Fin Cory is a peaceful species (1/10), while Bolivian Ram is generally mild-mannered (4/10). This modest difference means Bolivian Ram may occasionally assert dominance over Black Fin Cory.

Black Fin Cory and Bolivian Ram 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.

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 Black Fin Cory and Bolivian Ram 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 2–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Black Fin Cory and Bolivian Ram together, plan for an aquarium of at least 75 litres with a minimum length of 60 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), Smooth Gravel (Sensitive Barbels), Leaf Litter/Blackwater. 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. Black Fin Cory and Bolivian Ram 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 Black Fin Cory and Bolivian Ram.

Show 17 more tank sizes

Frequently Asked Questions

Can Black Fin Cory and Bolivian Ram 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 Black Fin Cory and Bolivian Ram need?

A minimum of 75 litres (tank length at least 60 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 Black Fin Cory and Bolivian Ram 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 Black Fin Cory or Bolivian Ram aggressive?

Black Fin Cory is peaceful (1/10) and Bolivian Ram is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Black Fin Cory and Bolivian Ram 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 Bolivian Ram's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Bolivian Ram 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
Issues or corrections?
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