My elephantnose has grown to 8inches in a year and still growing, hes fiesty and agressive (hes a big bully but hes no killer) but cant do alot of damage and frequently becomes worse off judging by his battle scars (he goes for my huge featherfin synos!), also fast swimming and extremely active at night. some people may think its overkill but I wouldnt put one in anything less than 90gallon if you have other bottom dwellers as competition. You need a bigger tank or it wont last long, also elephantnoses need pristine water conditions and quickly suffer without it!
What i would add is mines on a staple diet of frozen bloodworm but also eats frozen krill and brine shrimp. and i spot feed him with a turkey baster so he gets first dibbs!
They are notoriously difficult to keep alive but mines going strong, never had a problem and i dont do anything special, i do however have an extra 100gallons, x feet of space and 2 more filters than you have to play with so maybe thats the key to it!
Cant see it working unfortuantly but good luck trying. Amazing intelligent fish its just a shame you dont have the space.
Keep an eye out for a larger tank, some people just give em away! edit: ive got a 60gal sitting outside if u want it!
Ed
P.s mine has never touched a flake but trys to scoop up sinking granuals (the small orange/red things) dont know if he actually eats them tho!