The suspension is poured through a brine shrimp net to remove larger particles and most of the foam. The amount depends upon the feeding rate of that particular aquarium. Which brings me to color. If the DO is low over a sustained period of time - say a 5 to 7 days, you will notice the shrimp changing from a green to reddish. This is reportedly caused by development of an oxygen carrying pigment - hemoglobin or similar pigment.
Harvest is done with a standard aquarium net.
The larger netting allows immature shrimp to remain in culture. Cultures which are not overharvested will become self sustaining in 4 to 6 weeks. This brings me to another point. We rely upon donations and recycling everything possible.