Feed them less.
My fish would only eat sinking food (except for the Gourami), so I only fed them what they would eat before it hit bottom. This was before I got my Panda Corys. I would feed them 2-3x/day this way.
Now though, even the Rummynose and Cherry Barbs are eating it when it's floating. And the Cherry Barbs will also eat off the substrate, so I am adjusting my feeding again to feed some on top and have some reach bottom.
I do not stop the filters at feeding. I have two filters and adjust the smallest as far down as it will go. I put food in that front corner. I only feed once per day in the morning. I give brine shrimp occasionally.
TetraMin makes a food called Tropical Crisps. They float until the fish commence a ruckus while eating and slapping the food so it will drop.
I have used several brands over the years and have found the crisps to be a good choice. Most flakes turn to powder once you are about halfway done with the food container.
The only issue is small fish may not be able to swallow the crisps as they are about the size of dried oatmeal. You can crumble them though.