Can Alligator Pleco and Plain Silver Dollar Live Together?

Ideal Tank Mates

Yes, Alligator Pleco and Plain Silver Dollar are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. They occupy different areas of the water column, which reduces competition for space. A minimum tank size of 280 litres is recommended.


At a Glance

Alligator Pleco

Pterygoplichthys scrophus

Plain Silver Dollar

Metynnis hypsauchen

🐠Family Group
Alligator Pleco
Catfish
Plain Silver Dollar
Characins
Temperament
Alligator Pleco
Mostly Peaceful (3/10)
Plain Silver Dollar
Peaceful (2/10)
Temperature
✓ Compatible
Alligator Pleco
23–28°C
Plain Silver Dollar
24–28°C
pH Range
✓ Compatible
Alligator Pleco
6–7.5
Plain Silver Dollar
6–7.5
Hardness (dGH)
✓ Compatible
Alligator Pleco
4–15
Plain Silver Dollar
4–15
Water Type
✓ Compatible
Alligator Pleco
Freshwater Only
Plain Silver Dollar
Freshwater Only
Flow Preference
✓ Compatible
Alligator Pleco
Moderate
Plain Silver Dollar
Moderate
Min Tank Volume
Combined: 280 L
Alligator Pleco
280 L
Plain Silver Dollar
280 L
Swimming Level
✓ Different zones
Alligator Pleco
Bottom
Plain Silver Dollar
MiddleTop
🏷️Behavior Tags
Alligator Pleco
NocturnalPlant DestroyerDigger (Disturbs Substrate)Aggressive to same species/look-alikes
Plain Silver Dollar
Hyperactive / Fast SwimmerPlant DestroyerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Alligator Pleco and Plain Silver Dollar?

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.

Alligator Pleco
Plain Silver Dollar
Test both in my tank

Behaviour & Temperament

Alligator Pleco is a generally mild-mannered species (3/10), while Plain Silver Dollar is peaceful (2/10). This modest difference means Alligator Pleco may occasionally assert dominance over Plain Silver Dollar.

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

Worth noting: Alligator Pleco is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Plain Silver Dollar is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°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 4–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Alligator Pleco and Plain Silver Dollar together, plan for an aquarium of at least 280 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: Driftwood (Digestion/Hiding), Established Algae (Otocinclus), Sand (Sifters), Smooth Gravel (Sensitive Barbels). 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Alligator Pleco and Plain Silver Dollar.

Show 1 more tank size

Frequently Asked Questions

Can Alligator Pleco and Plain Silver Dollar live together?

Yes. Alligator Pleco and Plain Silver Dollar are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Alligator Pleco and Plain Silver Dollar need?

A minimum of 280 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 Alligator Pleco and Plain Silver Dollar together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Alligator Pleco or Plain Silver Dollar aggressive?

Alligator Pleco is generally mild-mannered (3/10) and Plain Silver Dollar is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Alligator Pleco and Plain Silver Dollar 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.

Does Alligator Pleco being nocturnal affect compatibility?

Alligator Pleco 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 Alligator Pleco during evening hours.


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