All it took was four bamboo sticks, four rubber bands and a 400 micron mesh to make a net. The net was suspended from the bamboo frame in the pond, keeping the water depth inside the nursery of 4-5 inches (10-13 cm). I added an airstone and a hose to constantly supply clean water to the nursery, pumped from the UV sterilizer (see my previous post "Filter Box Addition and Improvements"). Water pours from the hose into a "diffuser", a bunched up fine mesh, to keep the water movement to a minimum.
Since newly hatched brine shrimp size is up to 400 microns, I chose 400 microns mesh to keep them from escaping. Any finer mesh would get clogged more often with algae and the rest of the derbies.