Siamese Algae Eater

The Aquarist's Best Weapon Against Algae

The Siamese Algae Eater (Crossocheilus oblongus) is widely regarded as one of the most effective algae-eating fish available for freshwater aquariums. Unlike many so-called algae eaters, the true SAE actively consumes a wide variety of algae types — including the notoriously difficult black beard algae (BBA) that most other fish refuse to touch. Hardy, active, and peaceful when young, the SAE is a workhorse of the planted tank and a staple in aquascaping setups worldwide.

Overview

Why the True SAE?

• One of the few fish that actively eats black beard algae (BBA) — a planted tank keeper’s most stubborn foe
• Also consumes green spot algae, hair algae, thread algae, and film algae
• Active bottom and mid-level swimmer that grazes continuously throughout the day
• More effective than Chinese Algae Eaters or Flying Fox species for planted tank algae control

Identification Note

The true Siamese Algae Eater (Crossocheilus oblongus) is often confused with the Flying Fox (Epalzeorhynchos kalopterus) and the False SAE. Key identification features of the true SAE include a black stripe that runs continuously from the tip of the snout to the end of the tail fin (including through the tail), no distinct colour above the stripe, and the absence of a flap at the corner of the mouth.

Water Parameters & Tank Setup

• Temperature: 24 – 28°C (75 – 82°F)
• pH: 6.5 – 7.5
• General Hardness (GH): 5 – 15 dGH
• Tank Size: 100 L (25 gallons) minimum; they grow large and are active swimmers
• Filtration: Moderate to strong flow; well-oxygenated water preferred
• Plants & Decor: Ideal for planted tanks; provide driftwood and flat rocks for resting
• Cover: Tight-fitting lid recommended — SAEs are capable jumpers

Diet & Feeding

• Primary: Algae — grazes continuously on tank surfaces, plants, and decor
• Supplement: Sinking algae wafers, blanched zucchini, spinach, and spirulina-based foods
• Treats: Occasional live or frozen foods such as bloodworms and daphnia

Note: As SAEs mature and are well-fed, they may become less motivated to eat algae. Keep supplemental feeding moderate to maintain their algae-grazing behaviour.

Compatibility & Tank Mates

• Peaceful community fish — tetras, rasboras, danios, and corydoras
• Excellent companion for planted tanks with shrimp (generally safe with adult shrimp)
• Can become territorial with own species in smaller tanks — keep singly or in groups of 4+
• Avoid slow-moving, long-finned fish as tankmates when SAEs mature

The Siamese Algae Eater is an essential addition to any planted aquarium — a tireless, effective, and long-lived algae control solution that earns its place in every serious aquascape.