Sorry about the algae, but they likes it so I leaves it.
Also thats a shed skin stuck in the soil to the left, not a dead shrimp.
A blurry picture, I know, but these little guys are like 1 inch long and behind glass and water so my camera doesn't like taking photos of them.
Ehhhhh they help but as you can see they don't get all the algae.
I don't think they eat brown algae, on account of it being diatoms.
Sounds like you need more shrimp. Or the one from finding nemo