Net Breeders or Vibert Boxes?

Several of our participating schools this year will be raising their brook trout eggs in a vibert box while others will be using the standard net breeder for egg hatching.  We will be assessing the differences, if any, between these two styles of in-tank egg hatching.  See the pictures of vibert boxes in a tank below. 

A vibert box, pictured here, is what is commonly used when egg stocking a river or stream.  It is designed to sit on the bottom of the river, or tank in our situation , where the eggs hatch (sac fry) on the upper level and drop down into a larger area where they stay until most of their egg sacs are absorbed.  Once they feel safe,  the young fry swim through the holes on the bottom sides of the vibert box and into the rest of their world.