columbian shark help?

i got two of these beautiful cats on an impulse. i know that's never a good idea... but im guilty. any general information on the breed is much appreciated... however what i need to know now is if anyone has successfully housed them with african cichlids? also im holding them now in a 10 gallon until i can assure the big tank is safe for them (they're juvenile... still under 2 inches) and im wondering how long until the lack of space will be a problem. and last but not least im looking for advice on when i should start acclimating them to brackish conditions and how slowly should i add the salt? iv had a bad experience when it comes to cats and salt.