Working on the basis that Amano Shrimp and Otos predominantly algae feeders :
How do you know when you've got enough algae to feed Amano Shrimp and Otos?
... or ...
How do you know when your Amano Shrimp and Otos aren't getting enough food from the algae in your tank?
How do you know when you've got enough algae to feed Amano Shrimp and Otos?
... or ...
How do you know when your Amano Shrimp and Otos aren't getting enough food from the algae in your tank?