2 convicts in 15 gallon...

Considering their adult size no. A 40 gal breeder for a mated pair. IMO.
 
I had a breeding pair in a 15 once. As soon as the fry were free swimmers daddy slaughtered the mommy. This kind of puzzled me for quite some time. Only thing I can tell you is keep a close eye on them if your going to do it.
 
I'm not going to try it. I would like to keep some kind of cichild though b/c out water is very hard. I need to research some smaller cichilds.
 
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