It's next-to-impossible to determine how much food is required for a filter shrimp. Some keepers of
Atyopsis moluccensis choose to target feed their shrimp by grinding up fish food and placing it in the flow. This method is not without its problems in a 10 gallon tank as it's difficult to control pollution levels in such a small volume of water. My own two
Atyopsis moluccensis are not target fed but, they are in a larger mature tank that is heavily fed so they are constantly filtering something out of the column. They do appreciate a good flow, before I removed my Koralia 2 (2500lph) the shrimp would spend 95% of their time perched less than 3 inches from the output, they are built for fast-flowing water

Now they spend much of their time hanging upside down on the floating plants as that's where the highest levels of flow occur. They will seek out the current so it is good practice to ensure you have perches in the tank that will place the shrimp in the direct current. Also, be sure to have more perches than shrimp, despite their lack of weaponry they will bicker and constantly push for the prime spots.
I'm not sure that relying on the filter to remove uneaten food in the water column is a good idea, any such food would be better served in the water column than it would being trapped in the filter, where it will decompose and add to tank pollution. As a treat you can supplement their diet with baby brine shrimp. My own abhor bloodworm though, both live and frozen.