Can Dusky Millions Fish and Gold Nugget Pleco (L018) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Dusky Millions Fish and Gold Nugget Pleco (L018) are not recommended as tank mates due to no temperature overlap. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Dusky Millions Fish

Phalloceros caudimaculatus

Gold Nugget Pleco (L018)

Baryancistrus xanthellus

🐠Family Group
Dusky Millions Fish
Livebearers
Gold Nugget Pleco (L018)
Catfish
Temperament
Dusky Millions Fish
Peaceful (2/10)
Gold Nugget Pleco (L018)
Semi-Aggressive (6/10)
Temperature
✗ No overlap
Dusky Millions Fish
16–24°C
Gold Nugget Pleco (L018)
27–32°C
pH Range
✓ Compatible
Dusky Millions Fish
7–8
Gold Nugget Pleco (L018)
6–7.5
Hardness (dGH)
✓ Compatible
Dusky Millions Fish
8–20
Gold Nugget Pleco (L018)
2–12
Water Type
✓ Compatible
Dusky Millions Fish
Brackish Tolerant
Gold Nugget Pleco (L018)
Freshwater Only
Flow Preference
✗ No overlap
Dusky Millions Fish
Low
Gold Nugget Pleco (L018)
High
Min Tank Volume
Combined: 250 L
Dusky Millions Fish
40 L
Gold Nugget Pleco (L018)
250 L
Swimming Level
✓ Different zones
Dusky Millions Fish
TopMiddle
Gold Nugget Pleco (L018)
Bottom
🏷️Behavior Tags
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Gold Nugget Pleco (L018)
Territorial (Defends specific area)Aggressive to same species/look-alikesShy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Dusky Millions Fish and Gold Nugget Pleco (L018)?

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.

Dusky Millions Fish
Gold Nugget Pleco (L018)
Test both in my tank

Behaviour & Temperament

Dusky Millions Fish is a peaceful species (2/10), while Gold Nugget Pleco (L018) is moderately assertive (6/10). This notable difference means Gold Nugget Pleco (L018) may occasionally assert dominance over Dusky Millions Fish.

In terms of spatial distribution, Dusky Millions Fish prefers the Top (Surface) and Middle (Open Water) zones, whereas Gold Nugget Pleco (L018) occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Water Parameters

There is no temperature overlap between Dusky Millions Fish (16–24°C) and Gold Nugget Pleco (L018) (27–32°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 7 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 8–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Dusky Millions Fish and Gold Nugget Pleco (L018) together, plan for an aquarium of at least 250 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: Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Dusky Millions Fish prefers Low (Still Water) flow while Gold Nugget Pleco (L018) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Why This Pairing Usually Fails in Practice

Dusky Millions Fish and Gold Nugget Pleco (L018) 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 Dusky Millions Fish and Gold Nugget Pleco (L018).

Show 1 more tank size

Frequently Asked Questions

Can Dusky Millions Fish and Gold Nugget Pleco (L018) live together?

No. This combination is not recommended. Key incompatibilities — such as non-overlapping temperature ranges — make cohabitation unsafe.

What size tank do Dusky Millions Fish and Gold Nugget Pleco (L018) need?

A minimum of 250 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 Dusky Millions Fish and Gold Nugget Pleco (L018) together?

Unfortunately, there is no temperature range that satisfies both species. Dusky Millions Fish requires 16–24°C, while Gold Nugget Pleco (L018) needs 27–32°C.

Are Dusky Millions Fish or Gold Nugget Pleco (L018) aggressive?

Dusky Millions Fish is peaceful (2/10) and Gold Nugget Pleco (L018) is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Dusky Millions Fish and Gold Nugget Pleco (L018) need?

Both species overlap in the 7–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Gold Nugget Pleco (L018)'s fins?

Dusky Millions Fish is a known fin nipper. If Gold Nugget Pleco (L018) has long or flowing fins, there is a real risk of fin damage. Keeping Dusky Millions Fish in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Gold Nugget Pleco (L018)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Gold Nugget Pleco (L018) 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 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

Related Comparisons

Dusky Millions Fish & Balloon Molly

·

Possible with Caution
Dusky Millions Fish: PeacefulBalloon Molly: Peaceful

Dusky Millions Fish & Guppy

·

Possible with Caution
Dusky Millions Fish: PeacefulGuppy: Peaceful

Dusky Millions Fish & Least Killifish (Heterandria)

·

Possible with Caution
Dusky Millions Fish: PeacefulLeast Killifish (Heterandria): Peaceful

Dusky Millions Fish & Molly (Sailfin/Black/Dalmatian)

·

Possible with Caution
Dusky Millions Fish: PeacefulMolly (Sailfin/Black/Dalmatian): Peaceful

Dusky Millions Fish & Platy

·

Possible with Caution
Dusky Millions Fish: PeacefulPlaty: Peaceful

Dusky Millions Fish & Sailfin Molly

·

Possible with Caution
Dusky Millions Fish: PeacefulSailfin Molly: Peaceful

Gold Nugget Pleco (L018) & Adonis Pleco

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulAdonis Pleco: Peaceful

Gold Nugget Pleco (L018) & Chao Phraya Giant Catfish (Paroon Shark)

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulChao Phraya Giant Catfish (Paroon Shark): Peaceful

Gold Nugget Pleco (L018) & Dourada

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulDourada: Peaceful

Gold Nugget Pleco (L018) & Green Phantom Pleco (L200)

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulGreen Phantom Pleco (L200): Peaceful

Gold Nugget Pleco (L018) & Piraiba

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulPiraiba: Peaceful

Gold Nugget Pleco (L018) & Royal Pleco (L190)

·

Possible with Caution
Gold Nugget Pleco (L018): PeacefulRoyal Pleco (L190): Peaceful