Dont forget their a pair with tons of fry.I was looking at some adult salvinis in my lfs and they were in with firemouths, there was war but the salvinis were losing.It was a pair of sals up against a pair of firemouths, both adults.I think its to do with temperament, my convict has a bad temperament.The only reason i'm doing this combination is because I've seen it done so many times with success.Its trial and error i'm afraid.
Also keep in mind that they will be going into a 5.5x3x2.