Put some guppies in your tanks
I found that when the guppies were feeding this would stimulate the killies to do the same.
The other thing I found worked well was to increase the current in the tank, the flake moves around a little more "live food" like, which stimulates the killies to eat it.
Alternatively I can bring round some daphnia for you if you would like, I now feed my clowns and bi's once a week, and the tank looks like a snow dome for most of the week.
Let us know