Can Royal Pleco (L190) and Scarlet Badis Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Possible with Caution

Keeping Royal Pleco (L190) and Scarlet Badis together is possible but requires caution due to potential behavioral clashes and mismatched flow preferences. Provide a spacious tank of at least 450 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Royal Pleco (L190)

Panaque nigrolineatus

Scarlet Badis

Dario dario

🐠Family Group
Royal Pleco (L190)
Catfish
Scarlet Badis
Other
Temperament
Royal Pleco (L190)
Semi-Aggressive (5/10)
Scarlet Badis
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Royal Pleco (L190)
22–28°C
Scarlet Badis
18–26°C
pH Range
✓ Compatible
Royal Pleco (L190)
6.5–7.5
Scarlet Badis
6.5–8.5
Hardness (dGH)
✓ Compatible
Royal Pleco (L190)
5–15
Scarlet Badis
4–20
Water Type
✓ Compatible
Royal Pleco (L190)
Freshwater Only
Scarlet Badis
Freshwater Only
Flow Preference
✗ No overlap
Royal Pleco (L190)
High
Scarlet Badis
Low
Min Tank Volume
Combined: 450 L
Royal Pleco (L190)
450 L
Scarlet Badis
20 L
Swimming Level
Shared: 1 zone
Royal Pleco (L190)
Bottom
Scarlet Badis
MiddleBottom
🏷️Behavior Tags
Royal Pleco (L190)
Territorial (Defends specific area)NocturnalAggressive to same species/look-alikesPlant Destroyer
Scarlet Badis
Nano / Bite-sized (Predation Risk)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Aggressive to same species/look-alikesTerritorial (Defends specific area)
Stocking calculator

Can your tank handle Royal Pleco (L190) and Scarlet Badis?

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.

Royal Pleco (L190)
Scarlet Badis
Test both in my tank

Behaviour & Temperament

Royal Pleco (L190) is a moderately assertive species (5/10), while Scarlet Badis is generally mild-mannered (3/10). This modest difference means Royal Pleco (L190) may occasionally assert dominance over Scarlet Badis.

Royal Pleco (L190) and Scarlet Badis 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.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Royal Pleco (L190) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

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 Royal Pleco (L190) and Scarlet Badis 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 22°C and 26°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 Royal Pleco (L190) and Scarlet Badis together, plan for an aquarium of at least 450 litres with a minimum length of 150 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: Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - lighly covered, Sand (Sifters). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Royal Pleco (L190) is a plant destroyer, which conflicts with Scarlet Badis's requirement for live plants. Compromise where possible or prioritise the more critical need.

Royal Pleco (L190) prefers High (River/Stream) flow while Scarlet Badis needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

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. Royal Pleco (L190) and Scarlet Badis 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 Royal Pleco (L190) and Scarlet Badis.

Frequently Asked Questions

Can Royal Pleco (L190) and Scarlet Badis live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 450 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Royal Pleco (L190) and Scarlet Badis need?

A minimum of 450 litres (tank length at least 150 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 Royal Pleco (L190) and Scarlet Badis together?

Keep the aquarium between 22°C and 26°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Royal Pleco (L190) or Scarlet Badis aggressive?

Royal Pleco (L190) is moderately assertive (5/10) and Scarlet Badis is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Royal Pleco (L190) and Scarlet Badis need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Royal Pleco (L190)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Royal Pleco (L190) 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 Royal Pleco (L190) being nocturnal affect compatibility?

Royal Pleco (L190) 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 Royal Pleco (L190) during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
April 28, 2026
Last updated
April 28, 2026
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