I have kept ottocinclus (sp?) with bettas,with no probs.Ottos are small little fish that are pretty good cleaners.


A fat oto is a happy oto. An otocinclus should never be gaunt or have a skinny stomach. If it does look skinny, then something is wrong. Otocinclus are herbivores and they need to be constantly grazing on green matter in order to survive. Most tanks do not have enough algae to sustain a group of otocinclus so it is up to the fish keeper to provide supplemental food on a consistent basis.

Soft Green Algae
The main food of Otocinclus is algae. They will eat the soft green algae that grows on the surfaces of the tank and its contents. This surfaces include the inside of the tank walls, gravel, decorations, and plants. This soft algae isn't to be confused with green spot algae that you can barely get off with a razor blade. It's obvious that the rasping power of the otocinclus mouth isn't strong enough to remove that type of algae.

They also eat brown diatom algae, which is common in newly setup aquariums. Some have reported that they will really go to town on this algae and rid a tank of it in days. My soft water doesn't seem to produce much of the brown algae so unfortunately I haven't witnessed this firsthand.

So how can we grow this beneficial algae that otocinclus like? Well, we need to have an environment that is conducive to plant life too. Light and nutrients are important first steps. (More on this in the Happy Oto Tank article... coming soon.)

It seems that algae is the preferred food of otocinclus catfish. If they ignore all the other types of food you offer in the tank, there is a chance they may be getting enough from the algae itself. It's a good idea to first give them a while to notice what you've left in the tank as food, don't remove it right away. But as always, let their tummies be the guide!