Mixers, and lots of them...Try different types, as some go a bit soft and fall off the hook. Go to an animal feed place and look for the greyhound mixers, these are brown in colour and come in massive sacks for a tenner.
Look at the cat biscuits as well, the IAMS ones are really smelly and the carp love them.
Floating trout/Koi pellets...Just like using hemp on the surface, the carp hoover them off the top.
Suggest that feeding the small biscuits or pellets, and fishing a mixer, bread, or a small popup on a hair is a winner.
Good Luck. 