German blue ram and Panda corydoras
Can these two share a tank? The assessment below is derived from stored behavioural and environmental traits, not from a compatibility chart.
Should not be attempted. At least one factor is expected to cause harm.
- Minimum volume
- 105 L
- Minimum length
- 90 cm
- Factors considered
- 6
Concerns
Temperature requirements do not overlap: 26–30 °C for German blue ram against 20–25 °C for Panda corydoras. One animal would be kept outside its range permanently.
Derived from: environment.temperature on both records
German blue ram becomes markedly more aggressive while spawning. A pairing that has been peaceful for months can change within a day, so plan for where the other animal goes if it does.
Derived from: traits.breedingAggression
Both species occupy the bottom of the tank, so allow for the shared space when judging the footprint.
Derived from: zone and traits.activity on both records
Why it can work
- pH requirements overlap at 6–7.2.
- Hardness requirements overlap at 2–10 °dGH.
- Panda corydoras needs a group of at least 6. Kept in smaller numbers it is not simply lonely — shoaling species held below their threshold show chronic stress behaviour, colour loss and, in several species, increased aggression towards tankmates.
Conditions
Most interesting pairings are conditional on something. These are the things the keeper can actually change.
- At least 6 Panda corydoras, counted as one group
Derived, or documented?
These are different claims and are shown separately. The verdict above is derived from stored traits — arithmetic on AquariumHQ's own records. Whether the pairing is actually reported to work is a separate question, and for most pairs the honest answer is that we hold nothing.
Environmental compatibility
Derived from stored traits
Temperature, pH, hardness, size and behavioural traits compared between the two records. Sound as far as it goes, and it is not evidence that the pairing works.
Behavioural evidence
Widely reported in practice
Reported consistently across aquarium practice without a single citable source. Treated as real but not as measurement.
AquariumHQ's overall position
Two fish routinely sold into the same tank whose advised temperature ranges do not touch. Nothing about temperament, tank size or planting reconciles a five-degree gap, and the fish that loses is whichever one the heater is not set for.
What would change it: A warm-water corydoras. Corydoras sterbai overlaps the ram properly; the panda does not overlap it at all.
Factor by factor
- TemperatureDerived
The ram is advised at 26–30 °C and the panda corydoras at 20–25. There is no overlap at all. This pairing is not a compromise; it is two incompatible requirements.
- Floor competitionReported
Both work the substrate and the ram defends part of it. Reports describe corydoras being driven off feeding areas by spawning rams, which is a real but secondary problem.
- Both are sold as peaceful community fishReported
Which they are. Peacefulness is not the constraint here and describing either fish as peaceful answers a question nobody should be asking about this pairing.
| Depends on | How much |
|---|---|
| Tank size and dimensions | none |
| Life stage | none |
| The individual animal | none |
How good is the overlap?
Whether two ranges intersect is a necessary condition, not evidence. What matters is WHERE the shared band sits: an overlap at the top of one animal's range and the bottom of the other's is a forced compromise however wide it looks, and it is the case a simple intersection test cannot see.
| Dimension | Assessment | What that means here |
|---|---|---|
| Temperature | No overlap at all | Ranges do not meet: 26–30 against 20–25 °C. |
| pH | Workable | The shared band 6–7.2 pH is usable, though it does not sit centrally for both animals. |
| Hardness | Comfortable for both | The shared band 2–10 °dGH sits centrally in both ranges, with room to drift. |
No overlap at all
The ranges do not meet. One animal would be kept outside its range permanently.
Factor by factor
Every factor states what it rests on. Most are derived from the traits stored on both records — sound arithmetic on AquariumHQ's own data, and not a report about how the pairing actually goes. Where a factor says 'not known', the data is missing and saying so matters, because a missing factor and a favourable one look identical once both are absent.
| Factor | Basis | Finding |
|---|---|---|
| Temperature | Derived from stored traits | No overlap at all. Ranges do not meet: 26–30 against 20–25 °C. |
| pH | Derived from stored traits | Workable. The shared band 6–7.2 pH is usable, though it does not sit centrally for both animals. |
| Hardness | Derived from stored traits | Comfortable for both. The shared band 2–10 °dGH sits centrally in both ranges, with room to drift. |
| Body size | Derived from stored traits | Adult sizes are comparable at about 7 cm and 5 cm, so neither is a mouthful for the other. |
| Predation | Derived from stored traits | Highest predation risk in either direction is "low". |
| Territoriality | Derived from stored traits | Strongest territoriality across the pair is "mild". |
| Breeding aggression | Derived from stored traits | Breeding aggression reaches "moderate". A pairing peaceful for months can change within a day of a spawn. |
| Fin-nipping | Derived from stored traits | No nipper-and-target combination between these two. |
| Aggression | Derived from stored traits | Strongest intraspecific aggression across the pair is "mild". It bears on the pairing because a fish under pressure from its own kind redirects. |
| Social requirements | Derived from stored traits | Panda corydoras needs at least 6. A shoaling species held below its threshold shows chronic stress and, in several species, increased aggression towards tankmates. |
| Group-size dependency | Derived from stored traits | The outcome depends on group size as much as on the pairing: under-grouped shoalers nip more and hide more. |
| Tank zone | Derived from stored traits | Both occupy the bottom of the tank, so the shared space is under pressure. |
| Activity level | Derived from stored traits | Activity levels are compatible. |
| Food competition | Derived from stored traits | Both are omnivores feeding in the same part of the tank. |
| Risk to shrimp and snails | Derived from stored traits | Highest risk either animal poses to dwarf shrimp or snails is "near-certain". |
| Effect on plants | Derived from stored traits | Neither animal damages planting. |
| Tank dimensions | Derived from stored traits | The more demanding of the two needs at least 75 L and 60 cm of length before anything else is in the tank. Volume alone does not describe a home for a fish that swims in straight lines. |
| Life stage | Evidence-backed | Life-stage dependency: none. See the documented record. |
| Individual variation | Evidence-backed | Individual variation: none. |
Environmental overlap
| Parameter | Shared range | Reading |
|---|---|---|
| Temperature | No overlap | One animal would be kept outside its range. |
| pH | 6–7.2 | Stability matters more than the exact figure. |
| Hardness | 2–10 °dGH | Check your source water before committing. |
What this assessment cannot tell you
- Individual temperament varies, particularly in cichlids and in bettas, and can override a favourable verdict for German blue ram or Panda corydoras.
- The assessment is for the pair in isolation. A third species can change the outcome in either direction.
- Both animals are assessed at adult size, not at the size they are sold.
- A verdict is a statement about probability, not a guarantee.
Where the two water bands meet
Derived from the ranges AquariumHQ publishes for each species. The compatibility engine reads the same numbers; this is what they look like drawn on one axis.
Temperature (°C)
Scale: 0 to 36 °C.
No overlap. There is no temperature at which both species are inside their advised range.
pH (pH)
Scale: 4 to 9.5 pH.
Hardness (°dGH)
Scale: 0 to 30 °dGH.
Why the bands sit where they do
The overlap above is arithmetic. This is where the two numbers came from — the kind of water each animal is recorded from, and how much room that leaves.
These two animals come from different kinds of water, and that is where the arithmetic below comes from rather than from anything about their temperaments.
German blue ram
Soft forest stream
20–120 µS/cm · low flow · moderate oxygen
Panda corydoras
Hill stream and rapids
50–300 µS/cm · high flow · near saturation oxygen
- TemperatureGerman blue ram 26–30°CPanda corydoras 20–25°C
No overlap.
No overlap at all. There is no temperature, pH or hardness that suits both.
- pHGerman blue ram 5–7.2Panda corydoras 6–7.5
Both inside their range from 6–7.2 — 80% of the narrower animal’s range.
A wide window. Both animals are inside their own range across most of it, and the tank can be run without either sitting at an edge.
- General hardnessGerman blue ram 1–10 dGHPanda corydoras 2–12 dGH
Both inside their range from 2–10 dGH — 89% of the narrower animal’s range.
A wide window. Both animals are inside their own range across most of it, and the tank can be run without either sitting at an edge.
Computed from the ranges AquariumHQ publishes for each species, each of which records what it rests on — a source value, a habitat inference, a physiological requirement or a trade convention. Most are habitat inferences, and the species pages say which.