Originally Posted by Phoxly
I've never heard of having to keep Oto's in groups of 3, Cory's maybe, but Oto's I am always hearing do well with just 2 and rarely hang out.... =/
Actually three Oto's would be minimum numbers. Ditto for corydoras.
And as mentioned,most of the oto's are wild caught and feed almost exclusively on alage, and may or may not take to supplements like alage wafers and or vegetables that they would not see in the wild.
Googling info on care of otocinclus would be what I would do before I considered adding them to my aquarium. (most info recommends keeping them in groups)
I have kept them in planted tanks where they did well in group of six to twelve fish with stable water parameters,moderate to strong current,and oxygen rich water. Planted tanks were well established.
They (oto's) are intolerant of any fluctuations in temp or water chemistry (ie) ammonia,nitrites,and nitrAtes.
They are very industrious fish but do poorly in new tanks or tanks with little algae in my opinion.
As I was quite proficient at growing alage (plant's not so much) the little buggers did well for me and once discovered that they had spawned but iI fear the little ones were eaten by dwarf cichlids.