Generally compatible4 concerns

Cherry shrimp and Siamese algae eater

Can these two share a tank? The assessment below is derived from stored behavioural and environmental traits, not from a compatibility chart.

VerdictGenerally compatiblemoderate confidence

Usually works. Minor points to watch are listed below.

Minimum volume: 245 L
Minimum length: 150 cm
Factors considered: 8

Concerns

minortemperature

Temperature requirements overlap at 23–27 °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

minorinvertebrate risk

Adult shrimp should be safe, but Siamese algae eater will eat shrimplets. Expect the colony to hold steady rather than grow.

Derived from: traits.predation.shrimplets

minorterritory

Siamese algae eater defends a territory and both animals use the same part of the tank, so give the territory-holder a defensible area away from the main swimming space.

Derived from: traits.territoriality and zone on both records

minorzone competition

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 6.5–8.
Hardness requirements overlap at 6–15 °dGH.
Cherry shrimp needs a group of at least 10. 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.
Siamese algae eater needs a group of at least 4. 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.

Dense moss or leaf litter if you want the shrimp colony to increase in number
At least 10 Cherry shrimp, counted as one group
At least 4 Siamese algae eater, 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

Limited evidence

Some reports exist and they do not agree, or there are too few to generalise from. Read the derived assessment as the main basis.

AquariumHQ's overall position

A pairing whose answer changes as the fish grows. Sold as a shrimp-safe algae eater, and the animal it becomes is not the animal that claim was made about.

What would change it: Nothing the keeper controls, other than rehoming. The variable here is time, and the fish reaching adult size is not an accident to be avoided.

Factor by factor

Environmental overlapDerived
Overlapping ranges across all three parameters.
Size at purchase against adult sizeReported
FishBase records this species at 16 cm standard length, so the whole fish including its tail is longer still. It is sold at two to three centimetres as an algae-eating utility animal, and the gap between what is bought and what is kept is one of the largest in the catalogue.
Predation on shrimpletsDerived
Keeper reports conflict for adults, and the conflict is not resolved here. A three-centimetre specimen is no threat to anything; a sixteen-centimetre one is an actively foraging fish sharing a tank with animals a few millimetres long. Keepers reporting success and keepers reporting losses are frequently describing fish of very different sizes.
Competition at feedingDerived
An adult of this size takes prepared food vigorously and will outcompete shrimp at anything offered.

What the answer depends on. A single cell in a compatibility chart cannot hold any of these.
Depends on	How much
Tank size and dimensions	significant
Life stage	decisive
The individual animal	significant

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.

Each dimension assessed for the quality of the overlap, not merely its existence.
Dimension	Assessment	What that means here
Temperature	Workable	The shared band 23–27 °C is usable, though it does not sit centrally for both animals.
pH	Comfortable for both	The shared band 6.5–8 pH sits centrally in both ranges, with room to drift.
Hardness	Comfortable for both	The shared band 6–15 °dGH sits centrally in both ranges, with room to drift.

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.

2 evidence-backed17 derived0 not known

Factor	Basis	Finding
Temperature	Derived from stored traits	Workable. The shared band 23–27 °C is usable, though it does not sit centrally for both animals.
pH	Derived from stored traits	Comfortable for both. The shared band 6.5–8 pH sits centrally in both ranges, with room to drift.
Hardness	Derived from stored traits	Comfortable for both. The shared band 6–15 °dGH sits centrally in both ranges, with room to drift.
Body size	Derived from stored traits	Siamese algae eater reaches about 16 cm against 4 cm for Cherry shrimp — a ratio of 4.0. Size disparity drives opportunistic predation independently of temperament.
Predation	Derived from stored traits	Highest predation risk in either direction is "none".
Territoriality	Derived from stored traits	Strongest territoriality across the pair is "moderate".
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 "moderate". It bears on the pairing because a fish under pressure from its own kind redirects.
Social requirements	Derived from stored traits	Cherry shrimp needs at least 10; Siamese algae eater needs at least 4. 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	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 "moderate".
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 180 L and 120 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: decisive. FishBase records this species at 16 cm standard length, so the whole fish including its tail is longer still. It is sold at two to three centimetres as an algae-eating utility animal, and the gap between what is bought and what is kept is one of the largest in the catalogue.
Individual variation	Evidence-backed	Individual variation: significant.

Environmental overlap

Parameter	Shared range	Reading
Temperature	23–27 °C	Aim for the middle of the shared band.
pH	6.5–8	Stability matters more than the exact figure.
Hardness	6–15 °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 Cherry shrimp or Siamese algae eater.
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.

The two species

Cherry shrimpNeocaridina davidiThe most forgiving dwarf shrimp in the hobby and the usual first one. Colour strains — red, yellow, blue, green, orange — are all the same species, which is why mixing them produces wild-type brown offspring within a few generations.Siamese algae eaterCrossocheilus oblongusThe only widely available fish that reliably eats black brush algae, which is why it is bought. It also reaches 15 cm, becomes territorial with age and largely stops eating algae once well fed.