Tank Setup
- Tank size: 10 gallons minimum for a group of 6
- Maturity: Only add otos to tanks that have been running for 3+ months with established biofilm and algae growth
- Plants: Heavily planted tanks are essential — otos graze on leaf surfaces constantly
- Substrate: Sand or fine gravel preferred
Critical: Never add otocinclus to a new or recently cycled tank. They depend on biofilm and algae that only develops in mature aquariums. Many otos die in the first two weeks due to starvation in clean tanks.
Diet & Feeding
This is where many fishkeepers go wrong with otos. They are NOT like plecos and will not eat just anything:
- Primary food: Biofilm and soft green algae on tank surfaces
- Supplements: Blanched zucchini, cucumber, spinach (leave in tank overnight, remove in the morning)
- Algae wafers: Hikari Algae Wafers, Repashy Soilent Green
If your otos have round bellies, they're eating well. Sunken bellies indicate starvation — the most common cause of death.
Tank Mates
Otos are extremely peaceful and pair well with any small, non-aggressive fish. They are one of the few algae eaters safe for shrimp tanks, as they are strictly herbivorous and will never bother shrimp or fry.
Frequently Asked Questions
Why do otocinclus die so easily?
Most oto deaths are caused by: 1) starvation in clean/new tanks, 2) poor acclimation (they're sensitive to parameter swings), or 3) stress from wild-caught shipping. Buy from reputable sellers and only add to mature, well-planted tanks.