Can Reedfish (Ropefish) and Regan's Julie Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Reedfish (Ropefish) and Regan's Julie 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

Reedfish (Ropefish)

Erpetoichthys calabaricus

Regan's Julie

Julidochromis regani

🐠Family Group
Reedfish (Ropefish)
Oddballs
Regan's Julie
Cichlids - African
Temperament
Reedfish (Ropefish)
Mostly Peaceful (3/10)
Regan's Julie
Aggressive (7/10)
Temperature
✓ Compatible
Reedfish (Ropefish)
22–28°C
Regan's Julie
23–27°C
pH Range
✗ No overlap
Reedfish (Ropefish)
6–7.5
Regan's Julie
8–9
Hardness (dGH)
✓ Compatible
Reedfish (Ropefish)
5–20
Regan's Julie
10–25
Water Type
✓ Compatible
Reedfish (Ropefish)
Freshwater Only
Regan's Julie
Freshwater Only
Flow Preference
✓ Compatible
Reedfish (Ropefish)
Low
Regan's Julie
Moderate
Min Tank Volume
Combined: 180 L
Reedfish (Ropefish)
180 L
Regan's Julie
110 L
Swimming Level
Shared: 2 zones
Reedfish (Ropefish)
BottomMiddle
Regan's Julie
BottomMiddle
🏷️Behavior Tags
Reedfish (Ropefish)
Piscivore (Eats small/nano fish)Shrimp EaterJumper (Lid Required)NocturnalHyperactive / Fast SwimmerSlime Coat Eater (Attacks Flat Fish)
Regan's Julie
Territorial (Defends specific area)Aggressive to same species/look-alikesFry PredatorDigger (Disturbs Substrate)
Stocking calculator

Can your tank handle Reedfish (Ropefish) and Regan's Julie?

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.

Reedfish (Ropefish)
Regan's Julie
Test both in my tank

Behaviour & Temperament

Reedfish (Ropefish) is a generally mild-mannered species (3/10), while Regan's Julie is semi-aggressive (7/10). This notable difference means Regan's Julie may occasionally assert dominance over Reedfish (Ropefish).

Reedfish (Ropefish) and Regan's Julie both frequent the Bottom (Substrate) and Middle (Open Water) 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: Reedfish (Ropefish) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Reedfish (Ropefish) is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Reedfish (Ropefish) (6–7.5) and Regan's Julie (8–9) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Reedfish (Ropefish) and Regan's Julie together, plan for an aquarium of at least 180 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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Plants - Densely 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 Usually Fails in Practice

Reedfish (Ropefish) and Regan's Julie 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 Reedfish (Ropefish) and Regan's Julie.

Show 5 more tank sizes

Frequently Asked Questions

Can Reedfish (Ropefish) and Regan's Julie live together?

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

What size tank do Reedfish (Ropefish) and Regan's Julie need?

A minimum of 180 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 Reedfish (Ropefish) and Regan's Julie together?

Keep the aquarium between 23°C and 27°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Reedfish (Ropefish) or Regan's Julie aggressive?

Reedfish (Ropefish) is generally mild-mannered (3/10) and Regan's Julie is semi-aggressive (7/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Reedfish (Ropefish) and Regan's Julie need?

Their pH requirements do not overlap. Reedfish (Ropefish) prefers 6–7.5, while Regan's Julie needs 8–9. This makes them incompatible in the same water chemistry.

How do I manage Regan's Julie's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Regan's Julie 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.

Does Reedfish (Ropefish) being nocturnal affect compatibility?

Reedfish (Ropefish) is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Reedfish (Ropefish) during evening hours.

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?
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