I would never attempt a 10g tank for spawning convicts, even when small they are far too aggresive. Not only that, but once you factor in the growing fry you are going to need a lot of space. I have done it in a 20g but ideally something between 29 and 55g is best.
Convicts are a great species, I agree with the thread author. They have great personalitys and are very interesting, convicts were one of the first fish I ever owned and one of the fish I will probably own throughout my life no matter how deep in the hobby i get.