Compatibility brief
Can Common Pleco live with Oscar?
Risky. This mix is commonly discouraged for typical setups.
Common Pleco + Oscar: Aggression mismatch. Oscar is aggressive, while Common Pleco is peaceful. The aggressive fish will likely bully or harm the peaceful one. Real tanks add variables Fishori cannot model; treat this as a high-risk read, not certainty.
Compatibility score
Profile confidence: low
Order of checkstank volume vs adults → predation mouth gap → temperament / fin nipping → shared water windows.
600L
Combined minimum footprint reference for these two species: about 600L (larger active fish often want more length).
Common Pleco (peaceful) and Oscar (aggressive) are far apart on aggression — bullying or injury is a common outcome in average community layouts.
Assessment details
Aggression mismatch
Top issueOscar is aggressive, while Common Pleco is peaceful. The aggressive fish will likely bully or harm the peaceful one.
Compatible temperature range
Both fish can comfortably share similar water temperatures.
“Oscar is aggressive, while Common Pleco is peaceful”
Aggression mismatch
Next steps
Concrete changes, not "research more" filler.
Try instead
- →Build a species-only tank for the larger fish, or restock with fish too large to be eaten at adult sizes.
- LiveAquaria. Suckermouth / Common pleco (Hypostomus plecostomus)
Primary: large-aquarium retailer care guidance for the common / suckermouth Hypostomus type; emphasises long-term size and need for a very large system.
- Planet Catfish. Hypostomus plecostomus (Cat-eLog species sheet)
Primary: hobby species sheet: identification pointers, size expectations, and import caveats for the name 'common pleco' in trade.
- FishBase. Hypostomus plecostomus
Secondary: natural distribution and maximum size in the wild; cross-check 'common plec' in shops, which is often a different Hypostomus altogether.
- Seriously Fish. Astronotus ocellatus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Astronotus ocellatus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Astronotus ocellatus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Wikipedia. Astronotus ocellatus (oscar)
Encyclopaedia overview; use specialist aquarium sources for your stock's real temperature/pH/footprint needs.
Try this next
Build the full stocking list with Common Pleco + Oscar
Plan further
Try both species in the full-stock tank check, or open either fish profile for mates lists. Methodology explains how verdicts are produced.
Individual fish vary in personality. Fishori uses conservative hobby rules. Observe any new introduction closely, feed thoughtfully, and keep a quarantine or backup plan. This is not veterinary advice.
Profile data confidence: medium. Driven by the lower-confidence profile (Common Pleco): Based on typical aquarium care sources; trade names can be ambiguous, so details may vary between setups.

