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Description
[ARRIVING 14-MAY-2026] Otocinclus Arnoldi Great for Shrimp Tanks and Algae Control 2-4cmOtocinclus arnoldi (Arnolds Oto Catfish) Gentle algae grazer for established nano tanks Quick Facts Size: ~34 cm Tank size: 2060L+ Difficulty: Moderate Temperament: Peaceful Best kept: Groups (4+) Plant safe: Yes Is this for you? Good if: Established tank (34+ weeks) Looking for light algae grazing support Peaceful community setup Willing to keep a group Avoid if: New or unstable tank Expecting a full algae solution Aggressive tank mates Keeping only
Otocinclus arnoldi (Arnold’s Oto Catfish)
Gentle algae grazer for established nano tanks
Quick Facts
- Size: ~3–4 cm
- Tank size: 20–60L+
- Difficulty: 🟡 Moderate
- Temperament: Peaceful
- Best kept: Groups (4+)
- Plant safe: Yes
Is this for you?
✔️ Good if:
- Established tank (3–4+ weeks)
- Looking for light algae grazing support
- Peaceful community setup
- Willing to keep a group
❌ Avoid if:
- New or unstable tank
- Expecting a full algae solution
- Aggressive tank mates
- Keeping only one
Why this fish?
Otocinclus arnoldi is one of the smallest and most peaceful catfish available, making it ideal for nano aquariums. They stay small, are plant-safe, and gently graze on soft algae and biofilm without disturbing your setup.
Common mistakes
- Adding to new tanks → high mortality
- Expecting them to clean all algae
- Keeping them alone
- Not enough natural food (biofilm)
- Keeping with aggressive feeders
Care made simple
- Temperature: 22–26°C
- Diet: Biofilm + algae wafers
- Group size: 4+ recommended
- Water: Clean and stable
- Tank: Established setups only
Pair with
- Algae wafers
- Driftwood
- Sponge filter
- Live plants
Most issues with Otocinclus come from unstable tanks and lack of food — not shipping. If your tank is too new or too clean, risk increases significantly.
FAQ
Do Otocinclus eat all algae?
No. They mainly eat soft algae and biofilm.
Can I keep just one?
No. They do best in groups of 4 or more.
Why did my Otos die quickly?
Usually due to new tanks, lack of food, or stress.
Do they need feeding?
Yes. Supplement with algae wafers.
Shipping Notes
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Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
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