Clown loach and Nerite snail
Can these two share a tank? The assessment below is derived from stored behavioural and environmental traits, not from a compatibility chart.
Workable only in unusual circumstances. Not a pairing to plan around.
- Minimum volume
- 800 L
- Minimum length
- 200 cm
- Factors considered
- 6
Concerns
Clown loach eats snails. This is sometimes wanted and sometimes not — it applies equally to a snail you paid for and a snail you were trying to remove.
Derived from: traits.predation.snails
pH ranges overlap only across 7–7.5, which is tighter than most tap-water supplies hold naturally.
Derived from: environment.ph overlap width
Temperature requirements overlap at 25–28 °C, though the band does not sit centrally for both animals. Aim for the middle of it and keep the heater accurate.
Derived from: environment.temperature on both records
Why it can work
- Hardness requirements overlap at 6–12 °dGH.
- Clown loach needs a group of at least 5. 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.
- The two occupy different levels of the tank, which reduces direct competition for space.
Conditions
Most interesting pairings are conditional on something. These are the things the keeper can actually change.
- At least 5 Clown loach, counted as one group
- At least 800 L with a footprint of 200 cm or more, before counting anything else in the tank
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
Incompatible where the snail is wanted. The behavioural evidence is unusually clear because it is the fish's selling point.
Factor by factor
- Snail predation is the reason the fish is boughtReported
Loaches of several genera are acquired specifically to remove snails, and the behaviour does not distinguish a snail somebody paid for from a snail somebody wanted gone.
- Loach adult sizeDerived
Clown loaches reach a size most keepers do not plan for, and a larger loach handles a larger snail.
| Depends on | How much |
|---|---|
| Tank size and dimensions | none |
| Life stage | significant |
| The individual animal | minor |
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 | Workable | The shared band 25–28 °C is usable, though it does not sit centrally for both animals. |
| pH | Forced compromise — neither animal is where it wants to be | The shared band 7–7.5 pH sits at the top of one animal's range and the bottom of the other's. Both would be kept at their limits to accommodate the other. |
| Hardness | Workable | The shared band 6–12 °dGH is usable, though it does not sit centrally for both animals. |
Forced compromise — neither animal is where it wants to be
Both animals would be kept at the edge of their ranges to accommodate the other. Nothing here is a recommendation; it is the arithmetic of two incompatible requirements meeting at a point.
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 | Workable. The shared band 25–28 °C is usable, though it does not sit centrally for both animals. |
| pH | Derived from stored traits | Forced compromise — neither animal is where it wants to be. The shared band 7–7.5 pH sits at the top of one animal's range and the bottom of the other's. Both would be kept at their limits to accommodate the other. |
| Hardness | Derived from stored traits | Workable. The shared band 6–12 °dGH is usable, though it does not sit centrally for both animals. |
| Body size | Derived from stored traits | Clown loach reaches about 30 cm against 3 cm for Nerite snail — a ratio of 10.0. Size disparity drives opportunistic predation independently of temperament. |
| Predation | Evidence-backed | Highest predation risk in either direction is "near-certain". Reported: Loaches of several genera are acquired specifically to remove snails, and the behaviour does not distinguish a snail somebody paid for from a snail somebody wanted gone. |
| Territoriality | Derived from stored traits | Neither animal holds a territory. |
| Breeding aggression | Derived from stored traits | Neither becomes notably more aggressive while spawning. |
| 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 "none". It bears on the pairing because a fish under pressure from its own kind redirects. |
| Social requirements | Derived from stored traits | Clown loach needs at least 5. 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 | The two use different levels of the tank, which reduces direct competition for space. |
| Activity level | Derived from stored traits | Activity levels are compatible. |
| Food competition | Derived from stored traits | Different feeding strategies, so direct competition is limited. |
| 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 800 L and 200 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: significant. Clown loaches reach a size most keepers do not plan for, and a larger loach handles a larger snail. |
| Individual variation | Evidence-backed | Individual variation: minor. |
Environmental overlap
| Parameter | Shared range | Reading |
|---|---|---|
| Temperature | 25–28 °C | Aim for the middle of the shared band. |
| pH | 7–7.5 | Stability matters more than the exact figure. |
| Hardness | 6–12 °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 Clown loach or Nerite snail.
- 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.