Siamese algae eaters are active freshwater fish valued for grazing certain nuisance algae—especially when young—but they still need a proper diet and a suitably sized aquarium. They are strong swimmers that prefer clean, well-oxygenated water with moderate flow and stable parameters. As they mature, many individuals eat less algae and rely more on prepared foods, so they should not be treated as the only algae-control “solution.” In the right larger community tank, a true SAE is a useful, interesting companion fish.
Quick Specs
Water parameters
| Temperature: | 72–79°F (22–26°C). Keep it stable with good oxygenation and moderate current. |
| pH: | 6.5–7.5 (slightly acidic to neutral). |
| Hardness: | 5–15 dGH (moderate hardness is typically fine). |
| Other: | Ammonia and nitrites must be 0 ppm at all times. Keep nitrates as low as practical (ideally under ~20–30 ppm) with regular water changes and adequate filtration. SAEs are active riverine fish that benefit from good oxygen levels and some flow. As they mature, they often eat less algae and more prepared foods, so do not rely on them as the only algae-control strategy. |
| Water changes: | Change about 25–40% weekly to maintain stable water quality, especially in active community tanks. In heavily stocked tanks, 15–25% twice weekly can help keep nitrates down and oxygen levels high. |
Behavior & compatibility
Schooling Behavior: Siamese algae eaters are not true schooling fish, but they can be kept singly or in a small group. In groups they may establish a pecking order; in cramped tanks this can look like chasing. If you keep more than one, provide ample space and visual breaks.Temperament: They are generally peaceful, but can become boisterous and territorial as they mature, especially in smaller tanks or if multiple similar algae eaters are kept together. They are not typical fin-nippers, but may chase or harass tankmates in tight spaces.
Centrepiece: They are not usually a centerpiece fish; they are valued more as an active bottom/mid companion and algae grazer with useful behavior in larger community tanks.
Prolific or Livebearing:They are egg layers (not livebearers). Breeding in home aquariums is uncommon; they are not typically prolific in standard community setups.
Swimming zone:They spend time on the bottom and mid-water, grazing surfaces and swimming actively around the tank.
Interaction with Plants:Generally plant-safe. They may graze algae on leaves and surfaces. In rare cases, very hungry individuals may pick at soft plant edges, but most issues are solved by proper feeding.
Setup essentials
Lid: A tank cover is preferred. They are active and can jump when startled, and a cover also reduces evaporation.Filter: A filter is necessary. Use strong biological filtration with good mechanical capacity and moderate flow. SAEs are active swimmers and do best with good circulation and clean water.
Substrate: Sand or smooth gravel both work well. Choose what fits your plants and maintenance style. Include some rocks/wood and open swimming space; avoid sharp decor that can cause scrapes in active fish.
Lighting: Special lighting isn’t required for SAEs, but moderate aquarium lighting is preferred for viewing and plant growth. Strong lighting can increase algae, which they may graze when young.
Heater: A heater is preferred if room temperature is unstable. They do well at 22–26°C, so a heater is often used to keep temperature steady rather than to make it hot.
Air Pump: An air pump is preferred if surface agitation is limited, the tank runs warm, or stocking is heavy. They benefit from higher oxygen levels, especially with stronger flow setups.
Feeding Regimen
Feed 1–2 times per day. Do not rely on algae alone—offer quality pellets/flakes, algae wafers, and vegetables (zucchini, cucumber, spinach). Add occasional protein treats (daphnia/brine shrimp) in small amounts. As they mature, they often prefer prepared foods over algae, so consistent feeding is important.Lifespan
With proper care, Siamese algae eaters typically live about 8–10 years.Tank Mates
Good tank mates
robust peaceful community fish in appropriately sized tanks (larger tetras, rasboras, barbs with compatible temperament), corydoras (space dependent), bristlenose pleco (space dependent), many peaceful gouramis, snails (may be ignored), larger shrimp with cover.
Avoid
very aggressive fish, extremely timid fish that will be stressed by constant motion, and cramped tanks where chasing escalates.
Note
confirm species identity and plan tank size for the adult fish—SAEs need swimming space and good oxygenation.
Common problems + quick fixes
This is normal with maturity—continue feeding properly and manage algae with tank balance (light control, plant growth, manual removal).
Provide more space, add line-of-sight breaks, avoid overcrowding, and keep only one SAE unless the tank is large enough for a group.
Reduce feeding, increase filtration/mechanical cleaning, and perform 25–40% weekly water changes (or smaller changes twice weekly).
Verify you have true Crossocheilus siamensis; many lookalikes have different behavior and may be more aggressive or less effective algae grazers.
Interesting Facts
True Siamese algae eaters are often confused with similar “lookalike” species in stores, and those lookalikes may be more aggressive or less effective algae grazers. Young SAEs are often better algae grazers than adults, which is why long-term algae control usually depends on balancing light, nutrients, and plant growth. Their constant activity and grazing behavior make them feel like “maintenance crew,” but they still require strong filtration and space.