Can Australian Smelt and Contradens Pleco (Snowball Variant) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Australian Smelt and Contradens Pleco (Snowball Variant) 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

Australian Smelt

Retropinna semoni

Contradens Pleco (Snowball Variant)

Hypancistrus contradens

🐠Family Group
Australian Smelt
Other
Contradens Pleco (Snowball Variant)
Catfish
Temperament
Australian Smelt
Peaceful (1/10)
Contradens Pleco (Snowball Variant)
Mostly Peaceful (3/10)
Temperature
✗ No overlap
Australian Smelt
15–24°C
Contradens Pleco (Snowball Variant)
25–29°C
pH Range
✓ Compatible
Australian Smelt
6.5–8
Contradens Pleco (Snowball Variant)
5.8–7.5
Hardness (dGH)
✓ Compatible
Australian Smelt
5–20
Contradens Pleco (Snowball Variant)
4–15
Water Type
✓ Compatible
Australian Smelt
Brackish Tolerant
Contradens Pleco (Snowball Variant)
Freshwater Only
Flow Preference
✓ Compatible
Australian Smelt
Moderate
Contradens Pleco (Snowball Variant)
High
Min Tank Volume
Combined: 120 L
Australian Smelt
75 L
Contradens Pleco (Snowball Variant)
120 L
Swimming Level
✓ Different zones
Australian Smelt
TopMiddle
Contradens Pleco (Snowball Variant)
Bottom
🏷️Behavior Tags
Australian Smelt
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Fry PredatorJumper (Lid Required)
Contradens Pleco (Snowball Variant)
NocturnalShy / Slow Moving (Easily Stressed)Shrimp Eater
Stocking calculator

Can your tank handle Australian Smelt and Contradens Pleco (Snowball Variant)?

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.

Australian Smelt
Contradens Pleco (Snowball Variant)
Test both in my tank

Behaviour & Temperament

Australian Smelt is a peaceful species (1/10), while Contradens Pleco (Snowball Variant) is generally mild-mannered (3/10). This modest difference means Contradens Pleco (Snowball Variant) may occasionally assert dominance over Australian Smelt.

In terms of spatial distribution, Australian Smelt prefers the Top (Surface) and Middle (Open Water) zones, whereas Contradens Pleco (Snowball Variant) 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.

Worth noting: Contradens Pleco (Snowball Variant) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Australian Smelt is a known jumper, so a tight-fitting lid is essential.

Water Parameters

There is no temperature overlap between Australian Smelt (15–24°C) and Contradens Pleco (Snowball Variant) (25–29°C). This fundamental mismatch makes long-term cohabitation impractical.

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 Australian Smelt and Contradens Pleco (Snowball Variant) together, plan for an aquarium of at least 120 litres with a minimum length of 80 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 - lighly covered, Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). 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 Usually Fails in Practice

Australian Smelt and Contradens Pleco (Snowball Variant) 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 Australian Smelt and Contradens Pleco (Snowball Variant).

Show 10 more tank sizes

Frequently Asked Questions

Can Australian Smelt and Contradens Pleco (Snowball Variant) live together?

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

What size tank do Australian Smelt and Contradens Pleco (Snowball Variant) need?

A minimum of 120 litres (tank length at least 80 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 Australian Smelt and Contradens Pleco (Snowball Variant) together?

Unfortunately, there is no temperature range that satisfies both species. Australian Smelt requires 15–24°C, while Contradens Pleco (Snowball Variant) needs 25–29°C.

Are Australian Smelt or Contradens Pleco (Snowball Variant) aggressive?

Australian Smelt is peaceful (1/10) and Contradens Pleco (Snowball Variant) is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Australian Smelt and Contradens Pleco (Snowball Variant) 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.

Does Contradens Pleco (Snowball Variant) being nocturnal affect compatibility?

Contradens Pleco (Snowball Variant) 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 Contradens Pleco (Snowball Variant) 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?
Contact the editorial team

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