Hobby Artemia Sieves are specially constructed sieves, designed for collecting and rinsing newly hatched Artemia larvae. The standard sieve has a mesh size of 120 millimicrons, while the pack of four sieves has varying mesh sizes from 120 to 900 millimicrons. This allows for optimal sorting of Artemia, as well as other live foods.How do I use Hobby Artemia Sieves? Hobby Artemia Sieves are incredibly easy to use. Simply place the sieve over your sink and pour your egg, salt, and water solution into the sieve. The sieve will catch the newly hatched Artemia, while the rest will drain away. You can then feed your live Artemia to your fish.