Siamese Algae Eater Care Guide
The true Siamese Algae Eater (Crossocheilus oblongus) is one of the only fish that reliably eats black beard algae (BBA), the bane of planted tanks. Active, hardy, and effective, but beware of imposters sold under the same name.
Quick Facts
Tank Size Requirements
Warning: They grow much larger than sold
SAEs are typically sold at 1-2 inches but grow to 5-6 inches. They start peaceful but can become territorial with age, especially toward similar-looking fish. Plan for their adult size, not their juvenile size.
Minimum Requirements
- Minimum: 30 gallons for one SAE (55+ gallons for multiple)
- Shape: Long tanks preferred, they are active horizontal swimmers
- Plants: Heavily planted tanks provide grazing surfaces and hiding
- Current: Appreciate moderate flow, mimics their natural streams
- Lid: Required, they are capable jumpers
SAEs are active fish that need swimming space. They spend much of their time grazing algae from plants, driftwood, and decorations. In smaller tanks, they may become stressed and territorial as they mature.
Ideal Water Parameters
Hardy and Adaptable
SAEs are remarkably hardy fish that tolerate a wide range of water conditions. They are much more forgiving than many other algae eaters. Good water quality with proper filtration is still essential for long-term health, but they are not as demanding as more sensitive species.
Diet & Feeding
True SAEs are one of the few fish that actually eat black beard algae (BBA). They also consume hair algae and other types. However, as they mature and if overfed, they may become lazy about algae and prefer easier foods.
What They Eat
- Primary: Black beard algae (BBA), hair algae, other soft algae
- Supplemental: Algae wafers, spirulina tabs, blanched vegetables
- Protein: Occasional bloodworms, brine shrimp (as treats)
- Avoid: Overfeeding, they stop eating algae if overfed
Feeding Strategy
- Key: Keep them slightly hungry so they actively graze algae
- Supplement: Only if tank algae is insufficient
- Warning: Overfed SAEs become lazy algae eaters
Identifying True SAEs
Many fish are sold as "Siamese Algae Eaters" that are actually different species. The most common imposters are the Flying Fox and the Chinese Algae Eater, neither of which eat BBA and can become aggressive.
True SAE (Crossocheilus oblongus)
- Black stripe extends through the tail fin
- Stripe has ragged, uneven edges
- No colored stripe above the black one
- Clear or slightly yellow fins
- Rests on the bottom, propped on pectoral fins
Common Imposters to Avoid
- Flying Fox: Has a gold/yellow stripe above the black, colored fins
- Chinese Algae Eater: Suckermouth, becomes aggressive with age
- False SAE: Black stripe ends at tail base, doesn't extend into fin
Tank Mate Compatibility
SAEs are generally peaceful but can become territorial with age, especially toward similar-looking fish like Flying Foxes or other SAEs in smaller tanks.
Common Diseases & Treatment
Generally Hardy Fish
Siamese Algae Eaters are remarkably hardy and disease-resistant when kept in proper conditions. Most health issues arise from poor water quality, overfeeding, or stress from undersized tanks. Maintain good water quality and they rarely get sick.
Ich (White Spot)
White spots on body, scratching. Usually from stress or new fish.
Rx: Raise temp to 82-86°F + salt + medication
Swim Bladder Issues
Difficulty swimming, floating sideways. Usually from overfeeding or constipation.
Rx: Fast 2-3 days, then feed blanched peas
Keep them hungry, keep them healthy
Most SAE health issues come from overfeeding. A slightly hungry SAE is a healthy, actively algae-eating SAE. Resist the urge to feed them too much.
Quick Tips
- Verify you have a true SAE, the black stripe must extend INTO the tail fin
- Don't overfeed, hungry SAEs are effective algae eaters
- They grow to 5-6 inches, plan for adult size, not juvenile
- They can become territorial with age, large tanks help
- Avoid keeping with Red-tailed or Rainbow Sharks
- They may nibble on fine-leaved plants when hungry
- One of the only fish that reliably eats black beard algae
Frequently Asked Questions
Will SAEs actually eat black beard algae?
True Siamese Algae Eaters (Crossocheilus oblongus) are one of the few fish that reliably eat BBA. However, they may ignore it if overfed or if there are easier food sources available. Keep them slightly hungry for best algae control.
How do I know if I have a true SAE?
The key identifier is the black stripe: on a true SAE, it extends through the tail fin with ragged edges. Flying Foxes have a gold stripe above the black and colored fins. False SAEs have a stripe that ends at the tail base.
Why did my SAE stop eating algae?
The most common reason is overfeeding. If they have easy access to flakes, pellets, or other foods, they will prefer those over algae. Reduce feeding significantly and they should return to grazing. Age can also be a factor.
Can I keep multiple SAEs together?
In large tanks (55+ gallons), yes. In smaller tanks, they may become territorial with each other as they mature. A single SAE is often the best choice for tanks under 55 gallons.
Related Resources
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