one thing you will need to do is up the quality of ammonia removal... I don't care what method of power feeding you choose weather it's several time's a day or one big meal your fish will poop more(larger amount's ) and more often with out a doubt..
I would also think a variety of diet is the key factor... since bichers are generally curious eaters and would always try new food...
A normal day diet for my 14" del would comprise of
goldfishes,
guppies,
frogs,
platies and
baby catfishes, whichever is available.
Mine is greedy with
live shrimps and
superworms so have to feed these carefully.
Shrimps and superworms makes quite a mess also with their shells sometimes...
Just a common note of caution, senegals tend to overeat beyond their own limits... and might go to an extend of bursting their bellies or choking themselves... the other sp should not be much of a problem..
Beef heart will really make him grow fast. But dont feed too much of it because it can really be bad for them after a while. Mine loves any type of sea food that i buy at the supermarket!