Shrimp Ignoring food?

[ShrimpTime]

My shrimp have been acting active and healthy for a while now, but today when i feed them for the first time in a while they seem to be more invested in gathering off the plants/filter as opposed to going to the food, should I continue to not feed them and scoop out the food if its ignored for too long? is there any real way to tell if its a good time to feed the shrimp? Currently have 4 red cherry shrimp

[Newjohn]

When feeding,
Only feed enough that can be eaten in 20 minutes.
If you only have 4 Shrimp in your tank and if they are finding enough to eat off of the Plants and Substrate, I would not worry to much about feeding.
How old is the Tank ?

[ShrimpTime]

Its a little over 7 weeks old