10 gallon is too small for a pair, its not even that suitable for one. They are pretty aggressive little fish. I owned one, never got a chance to see how they breed, but I can imagine they are much more aggressive at that time. They are territorial, so caves or some type of structure would be a good idea for them to have. I would only keep a pair in a tank, if it were to be more of a community set up a much bigger tank is needed. Something like a 55 gallon. I think a 20 gallon long atleast is ok for a pair of these fish alone.