Should I buy it?
Siamese Algae Eater
Crossocheilus oblongus
Typical trade / ID note: Crossocheilus oblongus (typical reference)
Also known as: SAE, true SAE, Crossocheilus (trade name)
Fishori provides conservative planning guidance, not guarantees.
Based on typical aquarium care sources; trade names can be ambiguous, so details may vary between setups. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.
One of the few fish that genuinely eats black beard algae. Grows to 15 cm and becomes territorial with age. Not a low-maintenance algae solution.
Best for
Community tanks 100L or more with a black beard algae problem. One fish per tank.
Avoid if
You want a small permanent algae crew, or your tank is under 80L.
Top things that go wrong
- Shrimp & snails. Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Common mistakeMultiple SAEs for algae control. Two adults territory-fight and stop eating algae by the time they're fully grown.
Common trade-name warning
This fish is often sold under different names or species variants. Care guidance is based on typical aquarium examples rather than a single exact species. Shops frequently mislabel true Siamese algae eaters as Epalzeorhynchos "flying foxes", false SAEs, or other Crossocheilus. Identify fin pattern and barbels, not just the sticker.
What most shops don't tell you
- 1.Buying "SAE" without checking fin pattern. Flying fox and false SAE land in the same tank, and the dietary fit is not the same.
- 2.Stocking one for a 60L black brush problem. The adult outgrows the tank long before the algae loses.
- 3.Single fish or a group of four or more; a pair fights. Active feeders that beat slow cories to sinking food. Adults need a 100 cm run.
About this species
Siamese algae eaters are slim Asian cyprinids that work on hair and black brush algae. Adults reach 14 to 15 cm. Shops mislabel them as flying foxes and other Crossocheilus, so check fin pattern before you buy.
- Clown Pleco110L min · same group, comparable tank size
- Bristlenose Pleco80L min · same group, comparable tank size
- Otocinclus60L min · same fish family
- Royal pleco500L min · same fish family
- Common Pleco600L min · same fish family
- Beckford Pencilfishalso beginner peaceful, similar tank size
- Black Neon Tetraalso beginner peaceful, similar tank size
- Black phantom tetraalso beginner peaceful, similar tank size
- Bloodfin tetraalso beginner peaceful, similar tank size
- Bristlenose Plecoalso beginner peaceful, similar tank size
- Bronze corydorasalso beginner peaceful, similar tank size
- Boesemani Rainbowfish tank mateslists this fish as a safe and recommended mate
Plan grid
Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.
Swim zones
Planning trait chart
Six indices for comparing species on paper before you spend.
- Beginner ease60
- Peacefulness90
- Community fit82
- Small-tank fit100
- Hardiness76
- Energy54
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Common setup sketches
Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.
Rough 100L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safe directions on file include: Corydoras Catfish, Neon Tetra, Cherry Barb.
Tank mate intelligence
Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Siamese Algae Eater against your own reading before you buy.
Pair-level compatibility with this fish as anchor.
Read the blocking rule on each pair page before experimenting.
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Siamese Algae Eater + Corydoras Catfish
Behaviour, temperament, and what to watch
Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.
Siamese Algae Eater is peaceful in mixed company.
Stress / aggression triggers on file
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper, but individuals can still test fins under stress or in a crowded tank.
Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.
Territory: Not strongly territorial, but still claims a working area in the tank. Give it room to settle without overlapping the next species' patch.
Planted tanks: good — easy plant ideas
In the glass: typical and warning signs
- Moderate pacing — not hyperactive, not motionless.
- Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
- Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
- Low listed risk — still watch new introductions.
- Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
- If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Care parameters: water, food, inverts, grouping
Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.
Hardness
variable
Diet
herbivore
Vegetable matter, algae, and plant-based prepared foods. Long-term protein-only feeding causes bloat in herbivorous species.
Shrimp & snails
Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Kept singly or as a paired setup. Check the species profile before doubling up in one tank.
Breeding behaviour depends on the species. Research before you buy a mixed-sex group of this fish.
- Hold 24 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 8 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 100L published minimum for adults.
- Heater can hold 24–28°C without cooking cooler-water tank mates.
Explore and stocking hubs
Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.
Plan with tools
Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.
Filtration & heating
A 100L minimum tank needs a filter rated for at least 400L/hr turnover and a heater to hold 24–28°C reliably.
Plant suggestions
Siamese Algae Eater does well in planted tanks. Plants compatible with 24–28°C and pH 6–8:
Profile status: partially verified · Evidence tier: medium · 3 linked source(s). Fishori does not fabricate citations.
Fishori uses conservative planning rules based on these sources.
Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- LiveAquaria. Siamese Algae Eater (care profile)
Primary: retailer care sheet: tank size, water parameters, diet, and use in planted community tanks. Commercial copy may list C. siamensis; trade 'SAE' is often a mix of similar Crossocheilus. Identify the fish, not the bag label alone.
- Planet Catfish. Labeoninae (Crossocheilus and look-alikes)
Primary: Cat-eLog subfamily list for Crossocheilus and related Asian labeonins; the standard reference when separating SAE from Epalzeorhynchos 'flying foxes' and other doppelgängers.
- FishBase. Crossocheilus oblongus
Secondary: species-level taxonomy and size in the wild; reconcile with the fish in your tank, not every shop's name tag.
Evidence notes
- Crossocheilus taxonomy in the hobby is messy: Seriously Fish did not expose a working C. oblongus profile URL here, while retailers and forums split 'true SAE' vs C. langei/atrilines look-alikes. This entry pairs a LiveAquaria care page with the Planet Catfish labeonin index for ID context.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
- Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.