So I just checked these out, it seems their purpose is to scoop up the shrimp and hold them in the net. In a feeder it is my understanding that the mesh should be big enough that the shrimp should be able to squeeze through but it should be difficult for them. I would think that mesh is gonna be too small.
I think the mandarin is supposed to suck them through, which it seems like they should be able to do. But yeah, I get your point, I just don’t know what the perfect size is and given the fact that brine shrimp change size during the first 24 hours, it seems it would be hard to find a “perfect” mesh size.
Did you try reaching out to PaulB? I think I’ve seen him post recently.