NOTE that
@FroFro is talking about freeze
dried foods and NOT frozen.
The jury's out on whether or not to defrost frozen food before feeding.
I sometimes do, defrosting a cube, or a portion of a cube, in warm tank water. Adding this to the water flow scatters the food quickly across the tank. Whilst you can cut cubes into smaller pieces, defrosted food is easy to serve in smaller portions. This obviously stops excess falling away, to contribute to tank waste.
When I add the food frozen, it floats for a while and the fish will chase the cube about, pecking at it. (This is a useful feeding technique for me, when I want to do a head count.
).
NOTE that I don't have any fish with mouths begun to bite large frozen chunks. If I did, then I'd most likely defrost the food first.