Siamese algae eater

About the Siamese Algae Eater

The Siamese Algae Eater is widely regarded as one of the best natural algae-eating fish available for freshwater aquariums. Native to the rivers and streams of Thailand, Laos, and neighbouring parts of Southeast Asia, this active and peaceful species is particularly valued for its ability to consume nuisance algae, including the notoriously difficult Black Beard Algae (BBA).

Recognisable by the bold black stripe running from its nose through to the tail, the Siamese Algae Eater is an energetic swimmer that spends much of its day grazing on algae from plants, driftwood, rocks, and aquarium décor. Unlike many other algae eaters, true Siamese Algae Eaters remain effective algae grazers well into adulthood.

They thrive in well-planted aquariums with driftwood, rocks, open swimming space, and moderate water flow. As social fish, they do best in groups of three or more, although they can also be kept individually in suitable community aquariums. A varied diet of algae, spirulina wafers, sinking pellets, blanched vegetables, and frozen foods will keep them healthy once natural algae becomes limited.

Peaceful, hardy, and highly beneficial, the Siamese Algae Eater is an excellent addition to planted aquariums and community fish tanks.

Quick Care Guide

Scientific Name

Crossocheilus siamensis

Common Name

Siamese Algae Eater

Origin

Thailand, Laos, Cambodia, and Malaysia

Adult Size

14–16 cm

Temperament

Peaceful

Diet

Omnivore (Algae Grazer)

Minimum Tank Size

120 Litres

Temperature

23–28°C

pH

6.5–7.8

Water Hardness

5–15 dGH

Difficulty

Beginner

Lifespan

8–10 Years

Suitable For

Planted aquariums and peaceful community tanks

Frequently Asked Questions

Do Siamese Algae Eaters really eat Black Beard Algae?

Yes. True Siamese Algae Eaters are one of the few freshwater fish known to regularly consume Black Beard Algae (BBA), especially when young.

How can I tell a true Siamese Algae Eater from a Flying Fox?

A true Siamese Algae Eater has a jagged black stripe that extends through the tail fin, lacks gold edging above the stripe, and has clear fins. Flying Foxes have a smooth stripe, gold banding, and are generally more territorial.

What do Siamese Algae Eaters eat?

They eat soft algae, biofilm, spirulina wafers, sinking pellets, blanched zucchini, spinach, cucumber, and frozen foods such as bloodworms and brine shrimp.

Can Siamese Algae Eaters live with shrimp?

Yes. They are generally safe with adult shrimp and make excellent community fish, although very small shrimplets may occasionally be eaten.

Are Siamese Algae Eaters good for planted aquariums?

Absolutely. They are one of the best algae-control fish available and are widely used in heavily planted aquariums.

Common Mistakes

Buying the wrong species

Flying Foxes and False Siamese Algae Eaters are often misidentified and do not provide the same level of algae control.

Assuming algae is their only food

Once algae is depleted, they require a varied diet including quality sinking foods and vegetables.

Keeping them in very small aquariums

Adults become active fish reaching around 15 cm and require plenty of swimming space.

Keeping them with aggressive fish

They thrive in peaceful community aquariums where they can graze without constant stress.

Poor water quality

Excellent filtration and regular water changes help maintain healthy, active algae eaters.