Fish · Freshwater

Goldfish

Carassius auratus

The goldfish is not a fish for small bowls. It is a coldwater or temperate species with high bioload, significant growth and a need for strong filtration. Responsible care requires volume, oxygenation and stability.

The most common mistake is mixing it with tropical fish. It may survive intermediate temperatures, but that does not make the community biologically coherent long term.

Difficulty

Beginner

Aggression

10/10

Schooling

Medium

Size

25.00 cm

Minimum volume

120 L

Temperature

18.0-24.0 ºC

Zone

Whole tank

Lifespan

10 years

Quick profile scan

fish

Territoriality Low

Aggression 10/10

Activity Moderate

Thermal sensitivity Medium

Bioload High

Speed Moderate

Predation risk Opportunistic

Expert calculator

Check whether this species fits your aquarium

Analyze volume, parameters, behavior and relationships with other species.

Check compatibility

Expert read

Quick verdict

A practical summary to quickly decide whether it fits your aquarium.

Best for

Aquariums where its role fits: coldwater pet fish.

Avoid

Mixes marked as high risk or not recommended in manual relationships.

Compatible with

Has positive or conditional references with species such as Bristlenose pleco.

Typical risk

Bioload and adult volume should be planned with margin.

Aquarium zone

Where it lives best

Surface primary

Midwater primary

Bottom primary

Quick compatibility

Community signals

Shrimp

Conditional

Snails

Compatible

Slow fish

Conditional

Aggressive fish

Conditional

Small fish

Conditional

Large fish

Conditional

Delicate plants

Conditional

Buying decision

Before buying Goldfish

Review these points before adding it to your aquarium. They are practical notes based on its profile, ecological data, and known relationships.

Adult volume

Make sure your aquarium is above 120 L before buying it.

Territory and cover

Prepare visual cover and calm areas if it will live with other species.

Bioload

Plan filtration, water changes, and total stocking: this species can heavily load the system.

Parameters

Water conditions

6.5 - 8.0

5 - 20

3 - 12

Temperature

18.0 - 24.0 ºC

Growth and behavior

Juvenile to adult

Juvenile

As a juvenile it is usually more flexible and less dominant than an adult. Even so, it benefits from cover, stable parameters and tank mates that do not compete intensely in the whole aquarium.

Shift

The most important adult change is increased spatial and biological pressure, so the aquarium should be planned for the long term.

Adult

As an adult it behaves as a coldwater or temperate fish and needs space, tank mates and activity level to be well balanced. Its impact increases when bioload or competition is high.

Ecological profile

Role and biological pressure

Coldwater Pet Fish Coldwater Pet Fish Large High Wide Opportunistic

Profile: coldwater or temperate fish, with high bioload and primary use of the whole aquarium. It can adapt to calm communities, although it usually behaves better with compatible companions. It may show opportunistic predation toward fry or very small animals. Provide hiding places, visual barriers and enough room to prevent constant pressure.

Ecological radar

profile

Territoriality 24%

Aggression 100%

Activity 52%

Thermal sensitivity 52%

Bioload 78%

Common mistakes

What to avoid

Keeping it in tanks below the recommended adult volume.

Relations

Compatible with

✓

Bristlenose pleco

Conditional

LMain risk: Adult space Review conditions

Carassius auratus + Ancistrus cirrhosus: size difference, activity level or space pressure may cause stress, competition or insufficient usable room.

Japonica shrimp

Conditional

PMain risk: Predation Review conditions

Carassius auratus + Caridina japonica: shrimp, fry or small invertebrates may be at risk from curiosity, harassment or opportunistic predation.

Relations